Head Start categorical eligibility incorrectly aggregates foster care across family

[hua7450]

Bug

Head Start categorical eligibility (45 CFR 1302.12(c)(1)) has two aggregation bugs:

1. Foster care leaks to siblings: The formula uses add(person.tax_unit, ...) > 0 which sums all conditions — including was_in_foster_care — at the tax unit level. If one child was in foster care, all children in the tax unit are shown as categorically eligible. The regulation says "the child is in foster care" [(c)(1)(iv)] — it's child-specific.

2. Wrong aggregation entity: Uses tax_unit instead of spm_unit. The regulation's "family" concept for benefit eligibility maps to the economic family (SPM unit), not the tax filing unit. In multi-tax-unit households (e.g., grandparent + grandchild), the wrong entity excludes valid family members.

Expected behavior

Per 45 CFR 1302.12(c)(1):

• (ii) Public assistance (TANF, SSI, SNAP): family-level — if the family is eligible, all members qualify. Should aggregate at spm_unit.
• (iii) Homeless: household-level — all members in a homeless household qualify.
• (iv) Foster care: child-specific — only the individual child qualifies.

Regulatory sources

• 45 CFR 1302.12(c)
• ACF-IM-HS-22-03 — SNAP as public assistance (April 2022)
• 2016 Head Start Performance Standards Final Rule — SSI confirmed as public assistance