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Place of abode

1 rule

An individual shall not be treated as having the same principal place of abode of the taxpayer if at any time during the taxable year of the taxpayer the relationship between the individual and the taxpayer is in violation of local law.

in view

Whole section

Encodings · 1

cdcc_qualifying_individual26 USC § 21 (e)(1) · derived

26 USC 21(b)(1), 21(e)(1), 21(e)(5)

name: cdcc_qualifying_individual
kind: derived
entity: Person
dtype: Judgment
period: Year
source: 26 USC 21(b)(1), 21(e)(1), 21(e)(5)
metadata:
  proof:
    atoms:
      - path: versions[0].formula
        kind: definition
        source:
          corpus_citation_path: us/statute/26/21
      - path: versions[0].formula
        kind: exception
        source:
          corpus_citation_path: us/statute/26/21
versions:
  - effective_from: '2026-01-01'
    formula: |-
      (
          is_cdcc_child_dependent
          and age < cdcc_child_age_limit
          and not abode_relationship_violates_local_law
          and not noncustodial_parent_exception_applies
      )
      or (
          is_cdcc_dependent_disregarding_listed_subsections
          and physically_or_mentally_incapable_of_self_care
          and same_principal_place_of_abode_more_than_half_year
          and not abode_relationship_violates_local_law
          and not noncustodial_parent_exception_applies
      )
      or (
          is_spouse_of_taxpayer
          and physically_or_mentally_incapable_of_self_care
          and same_principal_place_of_abode_more_than_half_year
          and not abode_relationship_violates_local_law
      )

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▸rulespec code

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statutes/26/21.yaml

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Rules

Data relation qualifying_individual_of_tax_unit

#qualifying_individual_of_tax_unit

Data Relation

predicate: qualifying_individual_of_tax_unit
arity: 2

- name: qualifying_individual_of_tax_unit
  kind: data_relation
  data_relation:
    predicate: qualifying_individual_of_tax_unit
    arity: 2
    arguments:
      - TaxUnit
      - Person

cdcc_child_age_limit

Parameter

source: 26 USC 21(b)(1)(A)

- name: cdcc_child_age_limit
  kind: parameter
  dtype: Integer
  source: 26 USC 21(b)(1)(A)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: parameter
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '13'

cdcc_max_rate

Parameter

source: 26 USC 21(a)(2)

- name: cdcc_max_rate
  kind: parameter
  dtype: Rate
  source: 26 USC 21(a)(2)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: parameter
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '0.50'

cdcc_first_phaseout_floor

Parameter

source: 26 USC 21(a)(2)(A)

- name: cdcc_first_phaseout_floor
  kind: parameter
  dtype: Rate
  source: 26 USC 21(a)(2)(A)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: parameter
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '0.35'

cdcc_second_phaseout_floor

Parameter

source: 26 USC 21(a)(2)(B)

- name: cdcc_second_phaseout_floor
  kind: parameter
  dtype: Rate
  source: 26 USC 21(a)(2)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: parameter
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '0.20'

cdcc_phaseout_rate_reduction

Parameter

source: 26 USC 21(a)(2)(A)-(B)

- name: cdcc_phaseout_rate_reduction
  kind: parameter
  dtype: Rate
  source: 26 USC 21(a)(2)(A)-(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: parameter
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '0.01'

cdcc_first_phaseout_start

Parameter

source: 26 USC 21(a)(2)(A)

- name: cdcc_first_phaseout_start
  kind: parameter
  dtype: Money
  unit: USD
  source: 26 USC 21(a)(2)(A)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: amount
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '15000'

cdcc_phaseout_increment

Parameter

source: 26 USC 21(a)(2)(A)

- name: cdcc_phaseout_increment
  kind: parameter
  dtype: Money
  unit: USD
  source: 26 USC 21(a)(2)(A)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: amount
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '2000'

cdcc_second_phaseout_start_other

Parameter

source: 26 USC 21(a)(2)(B)

- name: cdcc_second_phaseout_start_other
  kind: parameter
  dtype: Money
  unit: USD
  source: 26 USC 21(a)(2)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: amount
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '75000'

cdcc_second_phaseout_start_joint

Parameter

source: 26 USC 21(a)(2)(B)

- name: cdcc_second_phaseout_start_joint
  kind: parameter
  dtype: Money
  unit: USD
  source: 26 USC 21(a)(2)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: amount
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '150000'

cdcc_second_phaseout_increment_other

Parameter

source: 26 USC 21(a)(2)(B)

- name: cdcc_second_phaseout_increment_other
  kind: parameter
  dtype: Money
  unit: USD
  source: 26 USC 21(a)(2)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: amount
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '2000'

cdcc_second_phaseout_increment_joint

Parameter

source: 26 USC 21(a)(2)(B)

- name: cdcc_second_phaseout_increment_joint
  kind: parameter
  dtype: Money
  unit: USD
  source: 26 USC 21(a)(2)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: amount
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '4000'

cdcc_one_qualifying_individual_expense_limit

Parameter

source: 26 USC 21(c)(1)

- name: cdcc_one_qualifying_individual_expense_limit
  kind: parameter
  dtype: Money
  unit: USD
  source: 26 USC 21(c)(1)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: amount
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '3000'

cdcc_two_or_more_qualifying_individuals_expense_limit

Parameter

source: 26 USC 21(c)(2)

- name: cdcc_two_or_more_qualifying_individuals_expense_limit
  kind: parameter
  dtype: Money
  unit: USD
  source: 26 USC 21(c)(2)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: amount
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '6000'

cdcc_student_spouse_deemed_income_one_qualifying_individual

Parameter

source: 26 USC 21(d)(2)(A)

- name: cdcc_student_spouse_deemed_income_one_qualifying_individual
  kind: parameter
  dtype: Money
  unit: USD
  source: 26 USC 21(d)(2)(A)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: amount
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '250'

cdcc_student_spouse_deemed_income_two_or_more_qualifying_individuals

Parameter

source: 26 USC 21(d)(2)(B)

- name: cdcc_student_spouse_deemed_income_two_or_more_qualifying_individuals
  kind: parameter
  dtype: Money
  unit: USD
  source: 26 USC 21(d)(2)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: amount
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '500'

cdcc_student_months_required

Parameter

source: 26 USC 21(e)(7)

- name: cdcc_student_months_required
  kind: parameter
  dtype: Integer
  source: 26 USC 21(e)(7)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: parameter
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '5'

cdcc_related_child_provider_age_limit

Parameter

source: 26 USC 21(e)(6)(B)

- name: cdcc_related_child_provider_age_limit
  kind: parameter
  dtype: Integer
  source: 26 USC 21(e)(6)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: parameter
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '19'

cdcc_dependent_care_center_individual_threshold

Parameter

source: 26 USC 21(b)(2)(D)(i)

- name: cdcc_dependent_care_center_individual_threshold
  kind: parameter
  dtype: Integer
  source: 26 USC 21(b)(2)(D)(i)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: parameter
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '6'

cdcc_outside_household_daily_hours_requirement

Parameter

source: 26 USC 21(b)(2)(B)(ii)

- name: cdcc_outside_household_daily_hours_requirement
  kind: parameter
  dtype: Integer
  source: 26 USC 21(b)(2)(B)(ii)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: parameter
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '8'

cdcc_2021_one_qualifying_individual_expense_limit

Parameter

source: 26 USC 21(g)(2)(A)

- name: cdcc_2021_one_qualifying_individual_expense_limit
  kind: parameter
  dtype: Money
  unit: USD
  source: 26 USC 21(g)(2)(A)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: amount
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '8000'

cdcc_2021_two_or_more_qualifying_individuals_expense_limit

Parameter

source: 26 USC 21(g)(2)(B)

- name: cdcc_2021_two_or_more_qualifying_individuals_expense_limit
  kind: parameter
  dtype: Money
  unit: USD
  source: 26 USC 21(g)(2)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: amount
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '16000'

cdcc_2021_first_phaseout_start

Parameter

source: 26 USC 21(g)(3)(B)

- name: cdcc_2021_first_phaseout_start
  kind: parameter
  dtype: Money
  unit: USD
  source: 26 USC 21(g)(3)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: amount
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '125000'

cdcc_2021_high_income_phaseout_start

Parameter

source: 26 USC 21(g)(4)(B)

- name: cdcc_2021_high_income_phaseout_start
  kind: parameter
  dtype: Money
  unit: USD
  source: 26 USC 21(g)(4)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: amount
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '400000'

cdcc_qualifying_individual

Derived

source: 26 USC 21(b)(1), 21(e)(1), 21(e)(5)

- name: cdcc_qualifying_individual
  kind: derived
  entity: Person
  dtype: Judgment
  period: Year
  source: 26 USC 21(b)(1), 21(e)(1), 21(e)(5)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: definition
          source:
            corpus_citation_path: us/statute/26/21
        - path: versions[0].formula
          kind: exception
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: |-
        (
            is_cdcc_child_dependent
            and age < cdcc_child_age_limit
            and not abode_relationship_violates_local_law
            and not noncustodial_parent_exception_applies
        )
        or (
            is_cdcc_dependent_disregarding_listed_subsections
            and physically_or_mentally_incapable_of_self_care
            and same_principal_place_of_abode_more_than_half_year
            and not abode_relationship_violates_local_law
            and not noncustodial_parent_exception_applies
        )
        or (
            is_spouse_of_taxpayer
            and physically_or_mentally_incapable_of_self_care
            and same_principal_place_of_abode_more_than_half_year
            and not abode_relationship_violates_local_law
        )

cdcc_qualifying_individual_count

Derived

source: 26 USC 21(a)(1), 21(b)(1), 21(c)

- name: cdcc_qualifying_individual_count
  kind: derived
  entity: TaxUnit
  dtype: Integer
  period: Year
  source: 26 USC 21(a)(1), 21(b)(1), 21(c)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: count_where(qualifying_individual_of_tax_unit, cdcc_qualifying_individual)

cdcc_expense_limit_before_exclusion

Derived

source: 26 USC 21(c)(1)-(2), 21(g)(2)

- name: cdcc_expense_limit_before_exclusion
  kind: derived
  entity: TaxUnit
  dtype: Money
  period: Year
  unit: USD
  source: 26 USC 21(c)(1)-(2), 21(g)(2)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: |-
        if cdcc_temporary_expansion_applies:
            if cdcc_qualifying_individual_count == 1:
                cdcc_2021_one_qualifying_individual_expense_limit
            else:
                if cdcc_qualifying_individual_count >= 2:
                    cdcc_2021_two_or_more_qualifying_individuals_expense_limit
                else:
                    0
        else:
            if cdcc_qualifying_individual_count == 1:
                cdcc_one_qualifying_individual_expense_limit
            else:
                if cdcc_qualifying_individual_count >= 2:
                    cdcc_two_or_more_qualifying_individuals_expense_limit
                else:
                    0

cdcc_dollar_limit

Derived

source: 26 USC 21(c)

- name: cdcc_dollar_limit
  kind: derived
  entity: TaxUnit
  dtype: Money
  period: Year
  unit: USD
  source: 26 USC 21(c)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: >-
        max(0, cdcc_expense_limit_before_exclusion -
        dependent_care_assistance_excludable_under_section_129)

cdcc_earned_income_limit

Derived

source: 26 USC 21(d)

- name: cdcc_earned_income_limit
  kind: derived
  entity: TaxUnit
  dtype: Money
  period: Year
  unit: USD
  source: 26 USC 21(d)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: |-
        if married_at_close_of_taxable_year and not treated_as_not_married_under_section_21:
            min(taxpayer_earned_income_for_cdcc, spouse_earned_income_for_cdcc)
        else:
            taxpayer_earned_income_for_cdcc

cdcc_creditable_expenses

Derived

source: 26 USC 21(a)(1), 21(b)(2), 21(c), 21(d)(1)

- name: cdcc_creditable_expenses
  kind: derived
  entity: TaxUnit
  dtype: Money
  period: Year
  unit: USD
  source: 26 USC 21(a)(1), 21(b)(2), 21(c), 21(d)(1)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
        - path: versions[0].formula
          kind: condition
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: |-
        if employment_related_expense_requirements_satisfied:
            min(employment_related_expenses_paid, min(cdcc_dollar_limit, cdcc_earned_income_limit))
        else:
            0

cdcc_first_phaseout_start_applicable

Derived

source: 26 USC 21(a)(2)(A), 21(g)(3)(B)

- name: cdcc_first_phaseout_start_applicable
  kind: derived
  entity: TaxUnit
  dtype: Money
  period: Year
  unit: USD
  source: 26 USC 21(a)(2)(A), 21(g)(3)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: |-
        if cdcc_temporary_expansion_applies:
            cdcc_2021_first_phaseout_start
        else:
            cdcc_first_phaseout_start

cdcc_first_phaseout_increments

Derived

source: 26 USC 21(a)(2)(A)

- name: cdcc_first_phaseout_increments
  kind: derived
  entity: TaxUnit
  dtype: Integer
  period: Year
  source: 26 USC 21(a)(2)(A)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: >-
        ceil(max(0, adjusted_gross_income - cdcc_first_phaseout_start_applicable) /
        cdcc_phaseout_increment)

cdcc_first_phaseout_rate

Derived

source: 26 USC 21(a)(2)(A), 21(g)(3)

- name: cdcc_first_phaseout_rate
  kind: derived
  entity: TaxUnit
  dtype: Rate
  period: Year
  source: 26 USC 21(a)(2)(A), 21(g)(3)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: |-
        max(
            if cdcc_temporary_expansion_applies: cdcc_max_rate else: cdcc_first_phaseout_floor,
            cdcc_max_rate - (cdcc_first_phaseout_increments * cdcc_phaseout_rate_reduction)
        )

cdcc_second_phaseout_start_applicable

Derived

source: 26 USC 21(a)(2)(B)

- name: cdcc_second_phaseout_start_applicable
  kind: derived
  entity: TaxUnit
  dtype: Money
  period: Year
  unit: USD
  source: 26 USC 21(a)(2)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: |-
        if filing_status == 1:
            cdcc_second_phaseout_start_joint
        else:
            cdcc_second_phaseout_start_other

cdcc_second_phaseout_increment_applicable

Derived

source: 26 USC 21(a)(2)(B)

- name: cdcc_second_phaseout_increment_applicable
  kind: derived
  entity: TaxUnit
  dtype: Money
  period: Year
  unit: USD
  source: 26 USC 21(a)(2)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: |-
        if filing_status == 1:
            cdcc_second_phaseout_increment_joint
        else:
            cdcc_second_phaseout_increment_other

cdcc_second_phaseout_increments

Derived

source: 26 USC 21(a)(2)(B)

- name: cdcc_second_phaseout_increments
  kind: derived
  entity: TaxUnit
  dtype: Integer
  period: Year
  source: 26 USC 21(a)(2)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: >-
        ceil(max(0, adjusted_gross_income - cdcc_second_phaseout_start_applicable) /
        cdcc_second_phaseout_increment_applicable)

cdcc_2021_high_income_phaseout_increments

Derived

source: 26 USC 21(g)(4)(B)

- name: cdcc_2021_high_income_phaseout_increments
  kind: derived
  entity: TaxUnit
  dtype: Integer
  period: Year
  source: 26 USC 21(g)(4)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: >-
        ceil(max(0, adjusted_gross_income - cdcc_2021_high_income_phaseout_start) /
        cdcc_phaseout_increment)

cdcc_rate

Derived

source: 26 USC 21(a)(2), 21(g)(4)

- name: cdcc_rate
  kind: derived
  entity: TaxUnit
  dtype: Rate
  period: Year
  source: 26 USC 21(a)(2), 21(g)(4)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: |-
        if cdcc_temporary_expansion_applies:
            if adjusted_gross_income > cdcc_2021_high_income_phaseout_start:
                max(0, cdcc_second_phaseout_floor - (cdcc_2021_high_income_phaseout_increments * cdcc_phaseout_rate_reduction))
            else:
                cdcc_first_phaseout_rate
        else:
            max(cdcc_second_phaseout_floor, cdcc_first_phaseout_rate - (cdcc_second_phaseout_increments * cdcc_phaseout_rate_reduction))

cdcc_potential

Derived

source: 26 USC 21(a)(1)

- name: cdcc_potential
  kind: derived
  entity: TaxUnit
  dtype: Money
  period: Year
  unit: USD
  source: 26 USC 21(a)(1)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: cdcc_creditable_expenses * cdcc_rate

treated_as_not_married_under_section_21

Derived

source: 26 USC 21(e)(3)-(4)

- name: treated_as_not_married_under_section_21
  kind: derived
  entity: TaxUnit
  dtype: Judgment
  period: Year
  source: 26 USC 21(e)(3)-(4)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: definition
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: |-
        legally_separated_under_decree
        or (
            filing_status == 2
            and maintains_household_principal_abode_of_qualifying_individual_more_than_half_year
            and furnishes_over_half_cost_of_household
            and spouse_not_member_of_household_during_last_six_months
        )

cdcc_married_filing_requirement_satisfied

Derived

source: 26 USC 21(e)(2)-(4)

- name: cdcc_married_filing_requirement_satisfied
  kind: derived
  entity: TaxUnit
  dtype: Judgment
  period: Year
  source: 26 USC 21(e)(2)-(4)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: condition
          source:
            corpus_citation_path: us/statute/26/21
        - path: versions[0].formula
          kind: exception
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: |-
        not married_at_close_of_taxable_year
        or filing_status == 1
        or treated_as_not_married_under_section_21

cdcc_claim_requirements_satisfied

Derived

source: 26 USC 21(e)(6), 21(e)(9)-(10), 21(h)(3)

- name: cdcc_claim_requirements_satisfied
  kind: derived
  entity: TaxUnit
  dtype: Judgment
  period: Year
  source: 26 USC 21(e)(6), 21(e)(9)-(10), 21(h)(3)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: condition
          source:
            corpus_citation_path: us/statute/26/21
        - path: versions[0].formula
          kind: exception
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: |-
        cdcc_married_filing_requirement_satisfied
        and service_provider_identifying_information_requirement_satisfied
        and qualifying_individual_tin_included_on_return
        and not paid_to_disallowed_related_individual
        and not possession_credit_or_payment_bars_united_states_credit

cdcc_refundable_under_2021_special_rule

Derived

source: 26 USC 21(g)(1)

- name: cdcc_refundable_under_2021_special_rule
  kind: derived
  entity: TaxUnit
  dtype: Judgment
  period: Year
  source: 26 USC 21(g)(1)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: condition
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: |-
        cdcc_temporary_expansion_applies
        and taxpayer_or_spouse_has_us_principal_abode_more_than_half_year

cdcc

Derived

source: 26 USC 21(a), 21(e)

- name: cdcc
  kind: derived
  entity: TaxUnit
  dtype: Money
  period: Year
  unit: USD
  source: 26 USC 21(a), 21(e)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: |-
        if cdcc_claim_requirements_satisfied and cdcc_qualifying_individual_count >= 1:
            min(cdcc_potential, tax_imposed_by_chapter_before_cdcc)
        else:
            0

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us/statute/26/21/e/1 — Place of abode · Axiom

Place of abode

1 rule

Official source

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Whole section

Encodings · 1

cdcc_qualifying_individual26 USC § 21 (e)(1) · derived

26 USC 21(b)(1), 21(e)(1), 21(e)(5)

name: cdcc_qualifying_individual
kind: derived
entity: Person
dtype: Judgment
period: Year
source: 26 USC 21(b)(1), 21(e)(1), 21(e)(5)
metadata:
  proof:
    atoms:
      - path: versions[0].formula
        kind: definition
        source:
          corpus_citation_path: us/statute/26/21
      - path: versions[0].formula
        kind: exception
        source:
          corpus_citation_path: us/statute/26/21
versions:
  - effective_from: '2026-01-01'
    formula: |-
      (
          is_cdcc_child_dependent
          and age < cdcc_child_age_limit
          and not abode_relationship_violates_local_law
          and not noncustodial_parent_exception_applies
      )
      or (
          is_cdcc_dependent_disregarding_listed_subsections
          and physically_or_mentally_incapable_of_self_care
          and same_principal_place_of_abode_more_than_half_year
          and not abode_relationship_violates_local_law
          and not noncustodial_parent_exception_applies
      )
      or (
          is_spouse_of_taxpayer
          and physically_or_mentally_incapable_of_self_care
          and same_principal_place_of_abode_more_than_half_year
          and not abode_relationship_violates_local_law
      )

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statutes/26/21.yaml

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Rules

Data relation qualifying_individual_of_tax_unit

#qualifying_individual_of_tax_unit

Data Relation

predicate: qualifying_individual_of_tax_unit
arity: 2

- name: qualifying_individual_of_tax_unit
  kind: data_relation
  data_relation:
    predicate: qualifying_individual_of_tax_unit
    arity: 2
    arguments:
      - TaxUnit
      - Person

cdcc_child_age_limit

Parameter

source: 26 USC 21(b)(1)(A)

- name: cdcc_child_age_limit
  kind: parameter
  dtype: Integer
  source: 26 USC 21(b)(1)(A)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: parameter
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '13'

cdcc_max_rate

Parameter

source: 26 USC 21(a)(2)

- name: cdcc_max_rate
  kind: parameter
  dtype: Rate
  source: 26 USC 21(a)(2)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: parameter
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '0.50'

cdcc_first_phaseout_floor

Parameter

source: 26 USC 21(a)(2)(A)

- name: cdcc_first_phaseout_floor
  kind: parameter
  dtype: Rate
  source: 26 USC 21(a)(2)(A)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: parameter
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '0.35'

cdcc_second_phaseout_floor

Parameter

source: 26 USC 21(a)(2)(B)

- name: cdcc_second_phaseout_floor
  kind: parameter
  dtype: Rate
  source: 26 USC 21(a)(2)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: parameter
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '0.20'

cdcc_phaseout_rate_reduction

Parameter

source: 26 USC 21(a)(2)(A)-(B)

- name: cdcc_phaseout_rate_reduction
  kind: parameter
  dtype: Rate
  source: 26 USC 21(a)(2)(A)-(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: parameter
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '0.01'

cdcc_first_phaseout_start

Parameter

source: 26 USC 21(a)(2)(A)

- name: cdcc_first_phaseout_start
  kind: parameter
  dtype: Money
  unit: USD
  source: 26 USC 21(a)(2)(A)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: amount
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '15000'

cdcc_phaseout_increment

Parameter

source: 26 USC 21(a)(2)(A)

- name: cdcc_phaseout_increment
  kind: parameter
  dtype: Money
  unit: USD
  source: 26 USC 21(a)(2)(A)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: amount
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '2000'

cdcc_second_phaseout_start_other

Parameter

source: 26 USC 21(a)(2)(B)

- name: cdcc_second_phaseout_start_other
  kind: parameter
  dtype: Money
  unit: USD
  source: 26 USC 21(a)(2)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: amount
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '75000'

cdcc_second_phaseout_start_joint

Parameter

source: 26 USC 21(a)(2)(B)

- name: cdcc_second_phaseout_start_joint
  kind: parameter
  dtype: Money
  unit: USD
  source: 26 USC 21(a)(2)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: amount
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '150000'

cdcc_second_phaseout_increment_other

Parameter

source: 26 USC 21(a)(2)(B)

- name: cdcc_second_phaseout_increment_other
  kind: parameter
  dtype: Money
  unit: USD
  source: 26 USC 21(a)(2)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: amount
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '2000'

cdcc_second_phaseout_increment_joint

Parameter

source: 26 USC 21(a)(2)(B)

- name: cdcc_second_phaseout_increment_joint
  kind: parameter
  dtype: Money
  unit: USD
  source: 26 USC 21(a)(2)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: amount
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '4000'

cdcc_one_qualifying_individual_expense_limit

Parameter

source: 26 USC 21(c)(1)

- name: cdcc_one_qualifying_individual_expense_limit
  kind: parameter
  dtype: Money
  unit: USD
  source: 26 USC 21(c)(1)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: amount
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '3000'

cdcc_two_or_more_qualifying_individuals_expense_limit

Parameter

source: 26 USC 21(c)(2)

- name: cdcc_two_or_more_qualifying_individuals_expense_limit
  kind: parameter
  dtype: Money
  unit: USD
  source: 26 USC 21(c)(2)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: amount
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '6000'

cdcc_student_spouse_deemed_income_one_qualifying_individual

Parameter

source: 26 USC 21(d)(2)(A)

- name: cdcc_student_spouse_deemed_income_one_qualifying_individual
  kind: parameter
  dtype: Money
  unit: USD
  source: 26 USC 21(d)(2)(A)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: amount
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '250'

cdcc_student_spouse_deemed_income_two_or_more_qualifying_individuals

Parameter

source: 26 USC 21(d)(2)(B)

- name: cdcc_student_spouse_deemed_income_two_or_more_qualifying_individuals
  kind: parameter
  dtype: Money
  unit: USD
  source: 26 USC 21(d)(2)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: amount
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '500'

cdcc_student_months_required

Parameter

source: 26 USC 21(e)(7)

- name: cdcc_student_months_required
  kind: parameter
  dtype: Integer
  source: 26 USC 21(e)(7)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: parameter
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '5'

cdcc_related_child_provider_age_limit

Parameter

source: 26 USC 21(e)(6)(B)

- name: cdcc_related_child_provider_age_limit
  kind: parameter
  dtype: Integer
  source: 26 USC 21(e)(6)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: parameter
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '19'

cdcc_dependent_care_center_individual_threshold

Parameter

source: 26 USC 21(b)(2)(D)(i)

- name: cdcc_dependent_care_center_individual_threshold
  kind: parameter
  dtype: Integer
  source: 26 USC 21(b)(2)(D)(i)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: parameter
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '6'

cdcc_outside_household_daily_hours_requirement

Parameter

source: 26 USC 21(b)(2)(B)(ii)

- name: cdcc_outside_household_daily_hours_requirement
  kind: parameter
  dtype: Integer
  source: 26 USC 21(b)(2)(B)(ii)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: parameter
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '8'

cdcc_2021_one_qualifying_individual_expense_limit

Parameter

source: 26 USC 21(g)(2)(A)

- name: cdcc_2021_one_qualifying_individual_expense_limit
  kind: parameter
  dtype: Money
  unit: USD
  source: 26 USC 21(g)(2)(A)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: amount
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '8000'

cdcc_2021_two_or_more_qualifying_individuals_expense_limit

Parameter

source: 26 USC 21(g)(2)(B)

- name: cdcc_2021_two_or_more_qualifying_individuals_expense_limit
  kind: parameter
  dtype: Money
  unit: USD
  source: 26 USC 21(g)(2)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: amount
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '16000'

cdcc_2021_first_phaseout_start

Parameter

source: 26 USC 21(g)(3)(B)

- name: cdcc_2021_first_phaseout_start
  kind: parameter
  dtype: Money
  unit: USD
  source: 26 USC 21(g)(3)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: amount
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '125000'

cdcc_2021_high_income_phaseout_start

Parameter

source: 26 USC 21(g)(4)(B)

- name: cdcc_2021_high_income_phaseout_start
  kind: parameter
  dtype: Money
  unit: USD
  source: 26 USC 21(g)(4)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: amount
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: '400000'

cdcc_qualifying_individual

Derived

source: 26 USC 21(b)(1), 21(e)(1), 21(e)(5)

- name: cdcc_qualifying_individual
  kind: derived
  entity: Person
  dtype: Judgment
  period: Year
  source: 26 USC 21(b)(1), 21(e)(1), 21(e)(5)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: definition
          source:
            corpus_citation_path: us/statute/26/21
        - path: versions[0].formula
          kind: exception
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: |-
        (
            is_cdcc_child_dependent
            and age < cdcc_child_age_limit
            and not abode_relationship_violates_local_law
            and not noncustodial_parent_exception_applies
        )
        or (
            is_cdcc_dependent_disregarding_listed_subsections
            and physically_or_mentally_incapable_of_self_care
            and same_principal_place_of_abode_more_than_half_year
            and not abode_relationship_violates_local_law
            and not noncustodial_parent_exception_applies
        )
        or (
            is_spouse_of_taxpayer
            and physically_or_mentally_incapable_of_self_care
            and same_principal_place_of_abode_more_than_half_year
            and not abode_relationship_violates_local_law
        )

cdcc_qualifying_individual_count

Derived

source: 26 USC 21(a)(1), 21(b)(1), 21(c)

- name: cdcc_qualifying_individual_count
  kind: derived
  entity: TaxUnit
  dtype: Integer
  period: Year
  source: 26 USC 21(a)(1), 21(b)(1), 21(c)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: count_where(qualifying_individual_of_tax_unit, cdcc_qualifying_individual)

cdcc_expense_limit_before_exclusion

Derived

source: 26 USC 21(c)(1)-(2), 21(g)(2)

- name: cdcc_expense_limit_before_exclusion
  kind: derived
  entity: TaxUnit
  dtype: Money
  period: Year
  unit: USD
  source: 26 USC 21(c)(1)-(2), 21(g)(2)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: |-
        if cdcc_temporary_expansion_applies:
            if cdcc_qualifying_individual_count == 1:
                cdcc_2021_one_qualifying_individual_expense_limit
            else:
                if cdcc_qualifying_individual_count >= 2:
                    cdcc_2021_two_or_more_qualifying_individuals_expense_limit
                else:
                    0
        else:
            if cdcc_qualifying_individual_count == 1:
                cdcc_one_qualifying_individual_expense_limit
            else:
                if cdcc_qualifying_individual_count >= 2:
                    cdcc_two_or_more_qualifying_individuals_expense_limit
                else:
                    0

cdcc_dollar_limit

Derived

source: 26 USC 21(c)

- name: cdcc_dollar_limit
  kind: derived
  entity: TaxUnit
  dtype: Money
  period: Year
  unit: USD
  source: 26 USC 21(c)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: >-
        max(0, cdcc_expense_limit_before_exclusion -
        dependent_care_assistance_excludable_under_section_129)

cdcc_earned_income_limit

Derived

source: 26 USC 21(d)

- name: cdcc_earned_income_limit
  kind: derived
  entity: TaxUnit
  dtype: Money
  period: Year
  unit: USD
  source: 26 USC 21(d)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: |-
        if married_at_close_of_taxable_year and not treated_as_not_married_under_section_21:
            min(taxpayer_earned_income_for_cdcc, spouse_earned_income_for_cdcc)
        else:
            taxpayer_earned_income_for_cdcc

cdcc_creditable_expenses

Derived

source: 26 USC 21(a)(1), 21(b)(2), 21(c), 21(d)(1)

- name: cdcc_creditable_expenses
  kind: derived
  entity: TaxUnit
  dtype: Money
  period: Year
  unit: USD
  source: 26 USC 21(a)(1), 21(b)(2), 21(c), 21(d)(1)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
        - path: versions[0].formula
          kind: condition
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: |-
        if employment_related_expense_requirements_satisfied:
            min(employment_related_expenses_paid, min(cdcc_dollar_limit, cdcc_earned_income_limit))
        else:
            0

cdcc_first_phaseout_start_applicable

Derived

source: 26 USC 21(a)(2)(A), 21(g)(3)(B)

- name: cdcc_first_phaseout_start_applicable
  kind: derived
  entity: TaxUnit
  dtype: Money
  period: Year
  unit: USD
  source: 26 USC 21(a)(2)(A), 21(g)(3)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: |-
        if cdcc_temporary_expansion_applies:
            cdcc_2021_first_phaseout_start
        else:
            cdcc_first_phaseout_start

cdcc_first_phaseout_increments

Derived

source: 26 USC 21(a)(2)(A)

- name: cdcc_first_phaseout_increments
  kind: derived
  entity: TaxUnit
  dtype: Integer
  period: Year
  source: 26 USC 21(a)(2)(A)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: >-
        ceil(max(0, adjusted_gross_income - cdcc_first_phaseout_start_applicable) /
        cdcc_phaseout_increment)

cdcc_first_phaseout_rate

Derived

source: 26 USC 21(a)(2)(A), 21(g)(3)

- name: cdcc_first_phaseout_rate
  kind: derived
  entity: TaxUnit
  dtype: Rate
  period: Year
  source: 26 USC 21(a)(2)(A), 21(g)(3)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: |-
        max(
            if cdcc_temporary_expansion_applies: cdcc_max_rate else: cdcc_first_phaseout_floor,
            cdcc_max_rate - (cdcc_first_phaseout_increments * cdcc_phaseout_rate_reduction)
        )

cdcc_second_phaseout_start_applicable

Derived

source: 26 USC 21(a)(2)(B)

- name: cdcc_second_phaseout_start_applicable
  kind: derived
  entity: TaxUnit
  dtype: Money
  period: Year
  unit: USD
  source: 26 USC 21(a)(2)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: |-
        if filing_status == 1:
            cdcc_second_phaseout_start_joint
        else:
            cdcc_second_phaseout_start_other

cdcc_second_phaseout_increment_applicable

Derived

source: 26 USC 21(a)(2)(B)

- name: cdcc_second_phaseout_increment_applicable
  kind: derived
  entity: TaxUnit
  dtype: Money
  period: Year
  unit: USD
  source: 26 USC 21(a)(2)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: |-
        if filing_status == 1:
            cdcc_second_phaseout_increment_joint
        else:
            cdcc_second_phaseout_increment_other

cdcc_second_phaseout_increments

Derived

source: 26 USC 21(a)(2)(B)

- name: cdcc_second_phaseout_increments
  kind: derived
  entity: TaxUnit
  dtype: Integer
  period: Year
  source: 26 USC 21(a)(2)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: >-
        ceil(max(0, adjusted_gross_income - cdcc_second_phaseout_start_applicable) /
        cdcc_second_phaseout_increment_applicable)

cdcc_2021_high_income_phaseout_increments

Derived

source: 26 USC 21(g)(4)(B)

- name: cdcc_2021_high_income_phaseout_increments
  kind: derived
  entity: TaxUnit
  dtype: Integer
  period: Year
  source: 26 USC 21(g)(4)(B)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: >-
        ceil(max(0, adjusted_gross_income - cdcc_2021_high_income_phaseout_start) /
        cdcc_phaseout_increment)

cdcc_rate

Derived

source: 26 USC 21(a)(2), 21(g)(4)

- name: cdcc_rate
  kind: derived
  entity: TaxUnit
  dtype: Rate
  period: Year
  source: 26 USC 21(a)(2), 21(g)(4)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: |-
        if cdcc_temporary_expansion_applies:
            if adjusted_gross_income > cdcc_2021_high_income_phaseout_start:
                max(0, cdcc_second_phaseout_floor - (cdcc_2021_high_income_phaseout_increments * cdcc_phaseout_rate_reduction))
            else:
                cdcc_first_phaseout_rate
        else:
            max(cdcc_second_phaseout_floor, cdcc_first_phaseout_rate - (cdcc_second_phaseout_increments * cdcc_phaseout_rate_reduction))

cdcc_potential

Derived

source: 26 USC 21(a)(1)

- name: cdcc_potential
  kind: derived
  entity: TaxUnit
  dtype: Money
  period: Year
  unit: USD
  source: 26 USC 21(a)(1)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: cdcc_creditable_expenses * cdcc_rate

treated_as_not_married_under_section_21

Derived

source: 26 USC 21(e)(3)-(4)

- name: treated_as_not_married_under_section_21
  kind: derived
  entity: TaxUnit
  dtype: Judgment
  period: Year
  source: 26 USC 21(e)(3)-(4)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: definition
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: |-
        legally_separated_under_decree
        or (
            filing_status == 2
            and maintains_household_principal_abode_of_qualifying_individual_more_than_half_year
            and furnishes_over_half_cost_of_household
            and spouse_not_member_of_household_during_last_six_months
        )

cdcc_married_filing_requirement_satisfied

Derived

source: 26 USC 21(e)(2)-(4)

- name: cdcc_married_filing_requirement_satisfied
  kind: derived
  entity: TaxUnit
  dtype: Judgment
  period: Year
  source: 26 USC 21(e)(2)-(4)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: condition
          source:
            corpus_citation_path: us/statute/26/21
        - path: versions[0].formula
          kind: exception
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: |-
        not married_at_close_of_taxable_year
        or filing_status == 1
        or treated_as_not_married_under_section_21

cdcc_claim_requirements_satisfied

Derived

source: 26 USC 21(e)(6), 21(e)(9)-(10), 21(h)(3)

- name: cdcc_claim_requirements_satisfied
  kind: derived
  entity: TaxUnit
  dtype: Judgment
  period: Year
  source: 26 USC 21(e)(6), 21(e)(9)-(10), 21(h)(3)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: condition
          source:
            corpus_citation_path: us/statute/26/21
        - path: versions[0].formula
          kind: exception
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: |-
        cdcc_married_filing_requirement_satisfied
        and service_provider_identifying_information_requirement_satisfied
        and qualifying_individual_tin_included_on_return
        and not paid_to_disallowed_related_individual
        and not possession_credit_or_payment_bars_united_states_credit

cdcc_refundable_under_2021_special_rule

Derived

source: 26 USC 21(g)(1)

- name: cdcc_refundable_under_2021_special_rule
  kind: derived
  entity: TaxUnit
  dtype: Judgment
  period: Year
  source: 26 USC 21(g)(1)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: condition
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: |-
        cdcc_temporary_expansion_applies
        and taxpayer_or_spouse_has_us_principal_abode_more_than_half_year

cdcc

Derived

source: 26 USC 21(a), 21(e)

- name: cdcc
  kind: derived
  entity: TaxUnit
  dtype: Money
  period: Year
  unit: USD
  source: 26 USC 21(a), 21(e)
  metadata:
    proof:
      atoms:
        - path: versions[0].formula
          kind: formula
          source:
            corpus_citation_path: us/statute/26/21
  versions:
    - effective_from: '2026-01-01'
      formula: |-
        if cdcc_claim_requirements_satisfied and cdcc_qualifying_individual_count >= 1:
            min(cdcc_potential, tax_imposed_by_chapter_before_cdcc)
        else:
            0