[MaxGhenis]

WIP. Counts eligible long-term care insurance premiums in the federal Schedule A medical subtotal.

Problem

itemized_medical_expenses adds only medical_expense_health_insurance_premiums and other_medical_expenses. 26 U.S.C. 213(d)(1)(D) counts premiums for a qualified long-term care insurance contract as medical care, up to the 213(d)(10) limit for the insured person's age at the end of the year.

Plan

• gov.irs.deductions.itemized.medical.long_term_care_premium_limit: 213(d)(10) limits 2013–2026 from the Rev. Procs., uprated after 2026.
• eligible_long_term_care_premiums (person): premiums up to the limit for the insured person's age. Long-term care premiums are recorded on the insured person.
• Self-employed coordination: eligible premiums enter the self-employed health insurance deduction (162(l)(2)(C), Form 7206 line 2); the Schedule A exclusion (162(l)(3)) takes medical premiums first, then long-term care premiums.
• itemized_medical_expenses_long_term_care_premiums: the eligible premiums inside the subtotal (computed or supplied).
• Sweep every consumer of itemized_medical_expenses and medical_expense_deduction for double counting (Ohio, Montana, Idaho, Missouri, New Jersey and others).
• YAML tests from the Rev. Procs. and Schedule A instructions; Hypothesis properties.
• Microsimulation impact through the hub queue.
• Axiom line, independent review.

🤖 Generated with Claude Code

[MaxGhenis]

Overlap with #10270 (draft), which edits itemized_medical_expenses too. It now sums medical_expense_health_insurance_premiums over the head and spouse only (tax_unit_non_dep_sum). IRC 213(a) counts expenses the taxpayer paid, and premium inputs sit on the payer (#10055), so a dependent's own premium payments stop counting. Every member's other_medical_expenses still counts, since the CPS records those by the person cared for.

This PR records eligible long-term care premiums on the insured person. When a dependent is the insured, the same question comes up: the parent's payment counts, the dependent's own doesn't. Whichever PR lands second will need to rebase that line and decide how long-term care premiums are attributed. The North Dakota renter refund in #10270 adds dependents' own premiums back (NDCC 57-02-08.1(5)(c)), and Montana's line 1 takes out only the filers' premiums. Both sit next to the long-term care handling here.