[hua7450]

Closes #10458

What and why

Connecticut's aged, blind and disabled Medicaid pathway (HUSKY C) subtracts the unearned income disregard from each assistance unit member's own unearned income. PolicyEngine subtracted the couple disregard (2 × the individual standard from 2024) once, from the couple's combined unearned income. When one spouse had less unearned income than the individual disregard, the model deducted up to the full individual disregard too much.

Rule	Source
"unearned income disregards are subtracted from the unit member's total gross monthly unearned income"	UPM 5030.15, section A
"applied unearned income is calculated by reducing the gross unearned income amount by the appropriate disregard"; "The assistance unit's total applied income is the sum of the unit's applied earnings, applied unearned income, and the amount deemed."	UPM 5045.10, sections C.1 and E

How the model applies it

• New by-state flag senior_or_disabled.income.disregard.applies_per_member, true for CT from 2015-01-01 (the first date in the disregard files; UPM 5030.15 A dates from a 2007 transmittal).
• Under the SSI couple computation, medicaid_optional_senior_or_disabled_countable_income sums, over the two spouses, each spouse's own monthly unearned income (ssi_unearned_income) capped at the individual disregard. That sum replaces the couple disregard. This equals subtracting the disregard from each spouse's income, flooring each result at zero, and adding them.
• When both spouses have at least the individual disregard, the result equals the old couple value. Individuals and other states do not change.

Example (2025): one spouse has $1,500 a month of unearned income and the other has $300.

Method	Monthly applied unearned income	Countable income each (annual)
Before: 1,800 − 1,070	730	4,380
After: (1,500 − 535) + max(300 − 535, 0)	965	5,790

Not changed

• Earned income: the $65 and one-half deductions still apply to the couple's combined earnings.
• The deemed-income variable for an ineligible spouse still uses the couple disregard.
• In-kind support and maintenance is still added to unearned income, as before.

Merge order

• Update Medicaid aged, blind and disabled pathway disregards and asset limits (CA, CT, MO, AR, OK, SC) #10364 sets Connecticut's 2026 disregard ($562 / $1,124) and edits the same lines of medicaid_optional_senior_or_disabled_countable_income.py, plus the end of the same test file. Merge 10364 first.
• After 10364 merges, this branch will merge main. It will use p.disregard.* in the formula, keep both sets of test cases, and replace the disregard/couple.yaml CT comment from 10364 (which points to issue 10458) with one saying the per-member rule now applies.

Test plan

• YAML cases (2025, individual disregard $535):
  • both spouses above the disregard ($5,280 each, the same as the couple value);
  • one spouse below it ($5,790 each, against $4,380 before).
• Source conflicts: not applicable.
• make format (ruff)
• Changelog fragment in changelog.d/
• CI passes (tests were not run locally)

No partner contract file in tests/policy/baseline/partners/ changes, and no partner case is in Connecticut.

🤖 Generated with Claude Code

[hua7450]

Closing. Connecticut's per-member couple disregard is out of scope for now. It is tracked in issue #10458. PR #10364 updates the couple comment and test name to point to that issue.