loading…

Married couples must file joint return

1 rule

If the taxpayer is married at the close of the taxable year, the credit shall be allowed under subsection (a) only if the taxpayer and his spouse file a joint return for the taxable year.

in view

Whole section

Encodings · 1

cdcc_married_filing_requirement_satisfied26 USC § 21 (e)(2) · derived

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

open in graph ↗

▸rulespec code

Shown source

statutes/26/21.yaml

Displaying the canonical repository encoding.

This encoding covers the parent provision us/statute/26/21; no dedicated encoding exists for this exact provision yet.

View on GitHub

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

loading…

us/statute/26/21/e/2 — Married couples must file joint return · Axiom

Married couples must file joint return

1 rule

Official source

graph ↗build calculator ↗

If the taxpayer is married at the close of the taxable year, the credit shall be allowed under subsection (a) only if the taxpayer and his spouse file a joint return for the taxable year.

in view

Whole section

Encodings · 1

cdcc_married_filing_requirement_satisfied26 USC § 21 (e)(2) · derived

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

open in graph ↗

▸rulespec code

Shown source

statutes/26/21.yaml

Displaying the canonical repository encoding.

This encoding covers the parent provision us/statute/26/21; no dedicated encoding exists for this exact provision yet.

View on GitHub

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