Apply the RI, SC, UT, VT, WV and WI rules for a filer who can be claimed as a dependent

[MaxGhenis]

Summary

Rhode Island, South Carolina, Utah, Vermont, West Virginia and Wisconsin have rules for a filer who can be claimed as a dependent that the model never applied. This PR applies the ones the federal fixes do not already cover, symmetric between head and spouse, on the settled inputs from #10024: claimability (claimable_as_dependent_on_another_return, read through head_or_spouse_is_dependent_elsewhere), an actual claim (claimed_as_dependent_on_another_return), and the Dependent Taxpayer Test with its filing exception (head_or_spouse_is_dependent_elsewhere_without_filing_exception).

Stacked on #10087 (claimable-filer-federal) and #10024; main is merged in (only wi_retirement_income_exclusion_tax.py conflicted, with #10026). Until #10087 also merges main, GitHub's diff includes main's newer commits; this PR's own changes are git diff abdf884d0f HEAD (abdf884d0f = the tree of #10087 merged with main 7dc0756).

Four related fixes that also change results when nobody is claimed (Vermont student loan interest, Vermont CTC phase-out, Utah's at-home parent credit, Wisconsin's homestead claimant) are in #10104 against main.

Formula	Rule now	Gate	Source
ri_property_tax_credit_eligible	Some filer is 65+ or disabled and is not claimed as a dependent; the age or disability and the claim test belong to the same spouse	actual claim	R.I. Gen. Laws 44-33-3(1): "Claimant shall not mean or include any person claimed as a dependent by any taxpayer"; household members "may determine between themselves as to who the claimant is"
ri_child_tax_rebate (2021 return)	No children on a return where the Dependent Taxpayer Test applies	DTT	44-30-103(b)(1): each child "whom the eligible taxpayer validly claims as a dependent"; IRC 152(b)(1)
sc_dependent_exemption, sc_young_child_deduction	Zero where the DTT applies	DTT	S.C. Code 12-6-1140(13): "each dependent must meet the eligibility requirements of Section 151 and 152"; 12-6-1160: a "dependent eligible for the South Carolina dependent exemption"
ut_total_dependents, ut_personal_exemption_additional_dependent_eligible, contributed ut_dependent_exemption_reform	Zero where the DTT applies	DTT	Utah Code 59-10-1018(1)(c): "an individual with respect to whom the claimant is allowed to claim a tax credit under Section 24"; (1)(g) birth-year dependent
ut_at_home_parent_credit_potential	No qualifying child where the DTT applies	DTT	59-10-1005(1)(a)(ii): the parent "claims the qualifying child as a dependent"
vt_personal_exemptions	Dependents only where the DTT does not apply (own/spouse exemptions already read claimability)	DTT	32 V.S.A. 5811(21)(C)(i): "provided that no exemption may be claimed for an individual who is a dependent of another taxpayer"
vt_ctc	Qualifying children are dependents of a return where the DTT does not apply	DTT	5830f(a): "entitled to a child tax credit under the laws of the United States", per "qualifying child, as defined under 26 U.S.C. § 152(c)"; the waiver reaches only "the taxpayer identification number requirements under 26 U.S.C. § 24(e) and (h)(7)"
vt_renter_credit	Zero only when every filer is actually claimed; fair market rent sized by personal exemptions	actual claim; exemptions_count	6066(c)(2): the claimant "may not be a person claimed as a dependent by any taxpayer"; 6066(b)(2): "a number of bedrooms equal to the number of personal exemptions"
wv_personal_exemption	$2,000 per exemption the return may claim, $500 once when it has none	exemptions_count	W. Va. Code 11-21-16; IT-140 (2025): "If box e is zero, enter $500 on line 6"; p. 26: "You cannot claim any dependents if you can be claimed as a dependent on another person's return"
wv_low_income_family_tax_credit_eligible, _fpg	Family size is the exemption count; no credit with zero exemptions	exemptions_count	11-21-22a(b): "the total number of exemptions that may be legally claimed"; IT-140 p. 13: "Individuals who file their income tax return with zero exemptions cannot claim the credit"
wi_standard_deduction, wi_retirement_income_exclusion_tax	When either filer can be claimed: lesser of the ordinary deduction and max($1,350, earned income + $450) in 2025, on both paths	claimability	Wis. Stat. 71.05(22)(f): for a taxpayer "with respect to whom an exemption ... is allowable to another person", indexed "in the manner prescribed by sections 1 (f) (3) to (6) and 63 (c) (4)"; Form 1 instructions: "You (or your spouse if filing a joint return) can be claimed"; worksheet amounts for 2021-2025 match the federal parameters
wi_additional_exemption	$250 per filer aged 65+ who cannot be claimed, whether or not anyone claims them	claimability	Form 1 line 10b (PDF p. 16): only for a spouse "allowed the $700 exemption on line 10a"
wi_homestead_income	$500 dependent deduction only where the DTT does not apply	DTT	Schedule H instructions (2025): a qualifying dependent "is or may be claimed as a dependent on your federal income tax return"
wi_childcare_expense_subtraction (2021), wi_childcare_expense_credit_potential	Childcare expenses read cdcc_qualifying_childcare_expenses, so a claimable filer's childcare for a nonqualifying child drops out	DTT (federal variable)	IRC 21(b)(2)(A)(ii): expenses "for the care of a qualifying individual"; Wis. Stat. 71.05(6)(b)43 and 71.07(9g) adopt section 21

Audit rows already fixed by #10024 or #10087 (not changed here)

• RI: exemptions (exemptions_count), EITC (federal eitc), care credit (federal cdcc).
• SC: EITC, care credit (count_cdcc_eligible, cdcc_relevant_expenses).
• UT: child tax credit (ctc_qualifying_child), EITC; homeowner/renter relief was already symmetric.
• VT: EITC, care credit (capped_cdcc, pre_obbba_capped_cdcc).
• WV: care credit (federal cdcc).
• WI: $700 exemption (exemptions_count); care credit counts (count_cdcc_eligible, capped_count_cdcc_eligible).

Hub comment (2026-10-10)

wi_additional_exemption now reads claimable_as_dependent_on_another_return, with a case for a filer aged 65 who can be claimed but is not claimed ($0) and a joint case under both labellings ($250). New cases also cover a filer who can be claimed but is not claimed under the actual-claim rules (still a Rhode Island relief and Vermont renter credit claimant), and the filing exception (South Carolina, Utah, Vermont and West Virginia dependents survive). Wisconsin's care subtraction and credit read the new cdcc_qualifying_childcare_expenses.

Readings for Max (queue via the US + core hub)

1. WV $500 exemption, joint returns. 11-21-16(d) gives $500 to "a resident individual whose exemption amount for federal tax purposes is zero by virtue of section 151(d)(2)", which reads per person; the IT-140 applies it once per return ("If box e is zero"). This PR follows the form: one claimable spouse gives $2,000, both give $500. Per-person reading: $2,500 and $1,000. An independent research pass (GPT-6.1 Sol, 2026-10-10) also recommends once per return. The Axiom module us-wv/statutes/11-21-16.yaml adds $500 on a supplied return-level flag on top of $2,000 per supplied federal exemption, so it settles neither reading.
2. VT renter credit, one claimed spouse. The unclaimed spouse can be the claimant (the claim is "personal to the claimant", 6063). Alternative: either spouse being claimed bars the joint claim ($0 instead of $1,771 in the test household).
3. VT renter credit, claimant with no exemptions. A filer who can be claimed but is not claimed is a valid claimant with no personal exemption. 6066(b)(2) points to a zero-bedroom fair market rent, which the parameter table (one to eight exemptions) lacks; the model uses the one-exemption row. Alternative: add zero-bedroom HUD FMRs by county.
4. WI dependent standard deduction amounts. Read from the federal parameters, since 71.05(22)(f) indexes the same base amounts the same way; the 2021-2025 Form 1 worksheets match exactly. Alternative: separate Wisconsin parameters.

Not modeled (listed, not implemented)

• RI individual health-coverage mandate (filing condition: "You cannot be claimed as a dependent by another taxpayer").
• SC special-needs adopted-child deduction and identity-protection deduction (higher cap for returns claiming dependents).
• VT homestead property tax adjustment (same claimant exclusion as the renter credit).
• WI private-school and college tuition deductions (dependent branches).
• WV surviving spouse's additional exemption (11-21-16(c)); family size excludes it anyway.
• WI homestead: the dependent's six-month residence test (71.52(5)); the model treats tax-unit dependents as household members.
• VT CTC identification rules by year (the waiver starts in 2023; the model applies no identification test in any year).

Other findings (not fixed here)

• vt_renter_credit never checks that the unit paid rent or prorates by months rented (6066(b)(1)(E)); any low-income Vermont unit gets the full-year credit.
• ut_total_dependents counts every dependent of the return; 59-10-1018(1)(c) counts only those for whom an IRC 24 credit is allowed (for example, not a dependent without a taxpayer identification number).

Invariants

1. Swap invariance of every changed output and state income tax under either head/spouse labelling, with claimability, actual claims and the filing exception drawn per spouse.
2. Monotonicity. Marking another filer as claimed never raises the dependent-based amounts, RI relief, VT exemptions and renter credit, WV exemption and family-credit eligibility and FPG, WI standard deduction, $250 exemption, homestead credit and care subtraction and credit. Left out by design: WI homestead income and the WV family credit amount, which rise when a deduction or exemption goes away.
3. Identities. Dependent-based amounts are zero where the Dependent Taxpayer Test applies; a return whose every filer is actually claimed gets no RI relief or VT renter credit; a West Virginia return with no exemptions gets the single $500.
4. Unchanged when nobody can be claimed, except the VT CTC no longer counting a young member who is not a dependent.

Tests

• YAML: variable-named cases for every changed formula: a single claimable filer, a joint return with one claimable spouse under both head/spouse labellings, both claimable, a nobody-claimed control, and claimable-but-unclaimed and filing-exception cases; expected values from the law and the repository parameters (arithmetic in each case's comments). Existing cases that fed tax-unit ages or used the filer as the child now use person inputs; the VT exemption cases that counted dependents on a claimable filer's return now expect the law's amounts. Results: pending (local run queued behind the shared heavy lock).
• Property test policyengine_us/tests/core/test_claimable_filer_ri_sc_ut_vt_wv_wi_invariants.py (Hypothesis plus a seeded population, 2021, 2023, 2025, 2026). Results: pending.

Microsimulation impact

Pending: default dataset, 2025 and 2026, #10087 merged with main vs this branch. The dataset sets no claimability inputs, so totals should not move.

axiom: R.I. Gen. Laws 44-33-3, 44-30-103 queued (draft RI) | S.C. Code 12-6-1140(13), 12-6-1160 queued (draft SC) | Utah Code 59-10-1018(1)(c),(g), 59-10-1005 queued (draft UT) | 32 V.S.A. 5811(21)(C), 5830f, 6066 queued (draft VT) | W. Va. Code 11-21-16, 11-21-22a queued (draft WV) | Wis. Stat. 71.05(22)(f), 71.05(23), 71.52(5), 71.07(9g) queued (draft WI); dispatch-ready rulespec-us drafts held for Max's go, not filed. No module on rulespec-us origin/main (16a6677190) derives claimability or tests a claimable filer: us-wv/statutes/11-21-16, us-ut/statutes/59-10-1018 and us-ri/statutes/44-30-103 take dependency counts as inputs, and the SC and WI 2026 cores hold dependent filers out.

🤖 Generated with Claude Code

Merge with main after #10087

Merged main after the reviewed federal changes landed in #10087.

• nm_medical_expense_credit.py, nm_medical_expense_credit.yaml, and ca_cdcc_relevant_expenses.yaml: kept main's reviewed federal content and later fixes. The branch copies exactly matched older federal head 35a2cbcbb9; this PR had no independent edits there.
• va_low_income_tax_credit_eligible.py, its YAML tests, and Hawaii's dependent_exemption_reform_test.yaml: kept main's later fixes and tests.
• vt_renter_credit.py: retained this PR's exemption-based fair market rent and actual-claim gate over main's half-up rounding and precision fixes. Its YAML keeps all 34 main cases plus this PR's six cases.

The diff against main contains exactly this PR's 40 own files, matching the original changes in substance. Two inherited changelog fragments already consumed on main were omitted. Required tests also exposed and fixed person/return projection and masked-county lookup errors, a string-projection error in the invariant helper, and stale or incomplete Vermont/Wisconsin fixtures (including explicit zero TANF for five wage-only deduction cases). Expected test values are preserved.

Validation: 227 cases passed across all 19 changed test files, one foreground process per file with the requested thread caps. Ruff 0.15.5 format/check passed for all 21 changed Python files; repository make format also passed.

[MaxGhenis]

Note from the US + core hub for this PR's owner (2026-10-10).

#10024 now has an approved head, c7f969f872, that splits one input into three facts:

• claimed_as_dependent_on_another_return: actually or expectedly claimed on another return (main's meaning, restored);
• claimable_as_dependent_on_another_return: can be claimed, whether or not it is; defaults to the input above when unspecified;
• dependent_claimant_filing_exception: the would-be claimant isn't required to file and files no return or only for a refund.

A reviewer of the claimable-filer-federal branch found that this PR's wi_additional_exemption change reads the actual claim where the rule turns on claimability. When you rebase onto the settled stack, point it at claimable_as_dependent_on_another_return, or at the helper head_or_spouse_is_dependent_elsewhere (which now means claimability), and add a case for a filer who can be claimed but is not.

Two related points from the same branch:

• State child-care credit formulas that read raw tax_unit_childcare_expenses have the gap found for Oregon and California; the federal branch adds cdcc_qualifying_childcare_expenses for them to read.
• The full consumer audit is in Make rules for a filer claimed elsewhere independent of which spouse is labelled head #10024's body.

[MaxGhenis]

Reply to the hub's note of 2026-10-10 (owner session), at head a35cdc6b83:

• wi_additional_exemption now reads claimable_as_dependent_on_another_return per spouse, with cases for a filer aged 65 who can be claimed but is not claimed ($0) and a joint return under both labellings ($250).
• All gates repointed to the settled inputs. Dependent counts (RI rebate, SC, UT including the contributed reform, VT exemptions and CTC, WI homestead $500) use head_or_spouse_is_dependent_elsewhere_without_filing_exception; RI property tax relief and the VT renter credit read the actual claim; WV exemptions and the WI standard deduction read claimability. New cases cover a claimable-but-unclaimed filer and the filing exception.
• Child-care expenses. wi_childcare_expense_subtraction and wi_childcare_expense_credit_potential read cdcc_qualifying_childcare_expenses. SC reads cdcc_relevant_expenses; RI, VT and WV read the federal credit.
• Rebased. Merged Apply the federal rules for a filer who can be claimed as a dependent #10087 (35a2cbc), then main (7dc0756); the only conflict was wi_retirement_income_exclusion_tax.py against Fix Wisconsin retirement election reporting and capital gain distributions #10026. Until Apply the federal rules for a filer who can be claimed as a dependent #10087 merges main too, GitHub's diff here includes main's commits; this PR's own change is git diff abdf884d0f a35cdc6b83.
• Split. The four fixes that change results when nobody is claimed (VT student loan interest, VT CTC phase-out, UT at-home parent credit, WI homestead claimant) moved to Fix Vermont student loan interest and CTC phase-out, Utah's at-home parent credit and Wisconsin's homestead claimant #10104 against main.

Pending: local YAML and property tests, microsims (2025 and 2026) and the independent review are queued; results will go in the body.