MA EAEDC SSI-eligibility exclusion lacks the income test (is_ssi_eligible vs uncapped_ssi)

[hua7450]

Part of #9330 (disconnected disability inputs audit).

Summary

MA EAEDC excludes disabled heads/spouses who are "SSI eligible" using is_ssi_eligible — but that model variable deliberately has no income test (categorical + resource + immigration only). The regulation's bar is an SSA eligibility determination, which includes SSA's income test. A disabled head whose income disqualifies them from SSI is legally EAEDC-eligible (subject to EAEDC's own financial tests) but is wrongly excluded.

Current code

policyengine_us/variables/gov/states/ma/dta/tcap/eaedc/eligibility/non_financial/ma_eaedc_eligible_disabled_head_or_spouse.py:18:

ssi_eligible = person("is_ssi_eligible", period)
return spm_unit.any(is_disabled & head_or_spouse & ~ssi_eligible)

Legal basis

• 106 CMR 702.710(B): a person "who is determined to be eligible for SSI or SSP … is ineligible for EAEDC" — an SSA determination, income test included.
• 106 CMR 703.191: EAEDC's own disability standard is an impairment "expected to last 60 days or more" substantially reducing capacity for work; SSA notification of SSI/SSDI disability qualifies automatically.

Impact

Incidence is narrowed by EAEDC's stricter financial tests, but the two programs' income-counting rules differ, so the wrongly-excluded set is not empty.

Proposed fix

Replace ~ssi_eligible with ~(person("uncapped_ssi", period) > 0) — income-inclusive and takeup-independent, matching "determined to be eligible" in steady state.

Secondary (per 703.191's automatic-qualification rule): consider broadening the disability leg to is_disabled | (social_security_disability > 0).

Context note: the sibling ma_eaedc_eligible_disabled_dependent_present correctly has no SSI carve-out (702.710 bars the SSI-eligible person from being the EAEDC grantee; a disabled dependent can be on SSI while the caretaker's category stands) — don't "harmonize" it.