[PavelMakarchuk]

Summary

The Maine dependent exemption credit (36 MRSA 5219-SS) counted every tax-unit dependent. It did not apply the federal identification tests, so it gave the credit for a dependent without an SSN, ITIN or ATIN, and for the children of a filer without any TIN.

This PR allows the credit only for a dependent with a positive section 24 amount (ctc_individual_maximum > 0), which is the rule that #10284 uses for me_fairness_credit_qualifying_children.

Stacked PR. This branch is cut from me-fairness-credit-odc-dependents (#10284), which is stacked on ctc-qualifying-children-filer-id (#10280). Neither is merged yet. The diff against #10284 is one formula, one YAML file and one changelog fragment. Retarget to main after #10280 and #10284 merge.

Law and forms

Source	Text
36 MRSA 5219-SS(1)	a credit "for each qualifying child and dependent of the taxpayer for whom the taxpayer was eligible to claim the federal child tax credit pursuant to the Code, Section 24"
2025 Form 1040ME instructions, line 13a (PDF p.5)	"Enter the number of qualifying children and dependents for whom you are eligible to claim the federal child tax credit or the credit for other dependents"
Same instructions, Schedule A lines 1 and 10 (PDF p.10)	the same test "under Internal Revenue Code, Section 24"; a non-filer completes a pro forma Form 1040 and Schedule 8812
2025 Dependent Exemption Tax Credit Worksheet, lines 1 and 3	counts the dependents "included on Form 1040ME, line 13a"
2025 Schedule 8812 instructions (PDF pp.1-2)	the ODC needs an SSN or ITIN for the filer (and the spouse on a joint return) and an SSN, ITIN or ATIN for the dependent

P.L. 2025, c. 650, Part K, §25 repealed the scheduled 2026 subsections (1-A, 2-A, 3-A), so the section 24 basis continues after 2025.

Change

me_dependent_exemption_credit_amount_person now reads ctc_individual_maximum (the child CTC or ODC amount for the person, before the phase-out). A dependent counts when either federal credit is allowed for that person:

• a CTC child, a 17-year-old or older dependent with a TIN, or a child with an ITIN but no SSN counts;
• a child whose filer has an ITIN but no SSN counts through the ODC (IRC 24(h)(4)(C));
• a dependent without an SSN, ITIN or ATIN, or any dependent on a return where a filer (on a joint return, either spouse) has no SSN or ITIN, does not count.

The explicit claimable-filer check from #10089 is removed, because ctc_individual_maximum already applies IRC 152(b)(1) to both the CTC and the ODC. The #10089 YAML cases in me_dependent_exemption_credit.yaml still pass.

Notes:

• The ODC citizenship and residency test (IRC 24(h)(4)(B)) is not modelled in ctc_adult_individual_maximum, so the Maine count inherits that gap.
• A reform that sets the federal CTC or ODC amount to zero now also removes dependents from this Maine credit, as with the fairness credits in Count dependents for the credit for other dependents in the Maine fairness credits #10284.

Tests

New cases in me_dependent_exemption_credit_amount_person.yaml (2025):

Case	Credit
Joint, SSN spouses, child 8 with no SSN, ITIN or ATIN	$0
Head of household with no SSN or ITIN, child 4 with an SSN	$0
Joint, one spouse with no SSN or ITIN, child 8 with an SSN	$0
Head of household with an ITIN only, child 3 with an SSN (ODC)	$610
Joint, SSN spouses, dependent 17 with an SSN (ODC)	$305

The three $0 cases fail on the old formula; the two positive cases guard the ODC path. The existing "Non CTC eligible child" case keeps its $610 result and its comment now names the ODC path.

Local runs (macOS, Python 3.14):

• Maine suite, test_batched.py policyengine_us/tests/policy/baseline/gov/states/me --mode per-subdir --workers 1: 657 passed, 0 failed (Count dependents for the credit for other dependents in the Maine fairness credits #10284 had 652; this PR adds 5).
• policyengine_us/tests/policy/contrib/states/me and edaa_end_child_poverty_act.yaml: 13 passed.
• policyengine_us/tests/core/test_claimable_filer_or_me_hi_invariants.py (reads me_dependent_exemption_credit): 4 passed.

No partner test uses a Maine household, so no partner contract changes.

axiom: TheAxiomFoundation/rulespec-us#1686 queued (5219-SS lawful section 24 dependents; blocked on the Maine corpus re-pin in TheAxiomFoundation/rulespec-us#1651). The 5219-SS TIN companions from this PR are posted at TheAxiomFoundation/rulespec-us#1686 (comment).

🤖 Generated with Claude Code

[hua7450]

Approving this PR's own change. It is stacked on 10284 and 10280, and 10280 still has changes requested.

I checked it against 36 MRSA 5219-SS, which allows the credit "for each qualifying child and dependent of the taxpayer for whom the taxpayer was eligible to claim the federal child tax credit pursuant to the Code, Section 24". I also checked Form 1040ME line 13a and the 2025 Dependent Exemption Tax Credit Worksheet, and I recomputed every case in both dependent exemption test files by hand.

• Law. P.L. 2025, c. 650, Part K, §25 did repeal the 2026 subsections (1-A, 2-A, 3-A), so the section 24 basis continues.
• Years. The credit and the federal credit for other dependents both start in 2018, so ctc_individual_maximum > 0 gives the line 13a count in every year the credit exists.
• Dropped check. Removing the explicit claimable-filer check from 10089 is safe. Both federal amounts already apply 152(b)(1), and the 10089 cases still recompute.
• Other tests. The three Maine credits integration cases still pass.

Nits:

1. Duplicate logic. This adds a second copy of the line 13a test, with its own legal comment, next to me_fairness_credit_qualifying_children from 10284. Both credits use the same form line, so one Maine person-level flag would keep them from drifting. For example, me_section_24_dependent would hold the comment and references once. The fairness count would then become adds = ["me_section_24_dependent"], and this variable would use it as defined_for. That flag is also the natural place to test eligibility rather than the federal amount (see the next point). It could land here or in 10284.
2. AFA reform. Because the test reads a federal amount, the afa_other_dependent_credit reform drops every non-CTC dependent from this credit: it sets ctc.amount.adult_dependent to 0 from 2025 and moves the credit for other dependents to its own variable. Your body notes the coupling; please name AFA there. Baseline results are exact.
3. Reference. The i1040s8.pdf href is the rolling current-year file, labelled as the 2025 instructions. Use https://www.irs.gov/pub/irs-prior/i1040s8--2025.pdf#page=1.
4. Filerless test cases. The edited "Non CTC eligible child" case and the two cases before it are one-person units with no head. The filer tests therefore pass vacuously, and the new comment describes a filer who is not there. Adding a head (age 30, default IDs) would make these cases exercise the filer rule.
5. Optional cases:
   • a 2024 joint return where one spouse has has_tin: false and a child aged 8: $0 at head, $300 before. This is the only pre-2025 change in this PR.
   • a 2025 child aged 4 with ssn_card_type: NONE and has_tin: true: $610.
   • one 2026 case.

Follow-ups, separate PRs:

• has_tin is labelled "Has TIN (ITIN or SSN)", but for dependents an ATIN also qualifies. This PR now relies on that input for a state credit.
• The three cases in credits/integration.yaml use absolute_error_margin: 1 on whole-dollar outputs of this credit.
• One case name in me_dependent_exemption_credit.yaml says "$300" but asserts the 2025 amount of 305.

Accepted limitations, already noted in your body: the 24(h)(4)(B) exclusion for dependents who are not U.S. citizens, nationals or residents, TIN issuance dates, and 24(g) disallowance periods have no model inputs.