Implement South Dakota Child Care Assistance (CCA)

[hua7450]

Summary

Implements South Dakota Child Care Assistance (CCA), the CCDF-funded child care subsidy administered by the South Dakota Department of Social Services.

This PR models the region-based weekly reimbursement schedule effective August 3, 2026. Because PolicyEngine calculates CCA monthly, the weekly-rate era is activated on August 1, 2026 so the entire August benefit period is not skipped. The prior hourly county-based schedule remains deferred.

Closes #8998.

What is modeled

• Child eligibility based on age, immigration status, and a reason for care.
• Protective services as an independent, child-specific reason for care.
• Employment eligibility using monthly hours equal to ceil(weekly hours × 4.3), an 80-hour minimum, and minimum-wage-equivalent earnings.
• Self-employment eligibility using at least 80 monthly hours and at least $580 in monthly net earnings at the current federal minimum wage.
• Full-time education and the federal CCDF activity-test input for approved pathways not modeled separately, including positive TANF activity. TANF enrollment alone does not establish activity.
• Initial income eligibility at the lesser of 209% FPL and 85% SMI, with continuing eligibility through 85% SMI.
• A 4% earned-income disregard, child-support-paid deduction, and exclusion of earnings for minors who are not the tax-unit head or spouse. A minor applicant parent's earnings remain countable.
• Weekly reimbursement rates by region, provider type, age group, and level of service, including the 1.75 special-needs multiplier.
• No reimbursement for a child with zero weekly care hours.
• A monthly family copay equal to 5% of countable income above 170% FPL, rounded down to a whole dollar.
• TANF family copay waivers and child-specific foster/protective-services waivers. In mixed-child units, an ordinary eligible child retains the full family copay.
• The final benefit as the lesser of billed expenses and the summed monthly reimbursement caps, minus the copay and floored at zero.

Review fixes included

• Removed TANF enrollment as a standalone activity pathway.
• Applied the prescribed 4.3 weekly-to-monthly work-hour conversion and upward rounding.
• Kept foster and protective-services copay treatment child-specific.
• Added whole-dollar copay flooring.
• Counted earnings of minor tax-unit heads and spouses.
• Activated the monthly weekly-rate model for August 2026.
• Previously addressed work thresholds, protective-services reason-for-care eligibility and copay waiver, and zero-care-hour reimbursement.

Regulatory sources

• ARSD 67:47:01 — Assistance with Child Care Costs
• BEES Child Care Assistance Policy Manual
• 2026 Child Care Subsidy Co-Payments
• CCA Weekly Reimbursement Rates, effective August 3, 2026
• Provider Rate Regions, effective August 3, 2026

Known limitations

• The hourly county-based schedule before August 2026 is not modeled.
• The exact August 3 transition is approximated at the monthly level; the benefit is not prorated within August.
• Certification-period timing, including the continuation pathway for a child who turns 13, is not represented.
• Foster-parent income/asset exclusions and the protective-services asset exception are not yet modeled child-by-child.
• Gambling and lottery winnings and their special lump-sum timing rules are not included in countable income.
• Provider-count, waiting-list, overnight-care, and administrative-compliance rules are not simulated.

Validation

• make format — passed, including Ruff format and Ruff check.
• Focused SD CCA suite — 138 passed.
• Complete South Dakota baseline suite — 189 passed.
• Exact July 31/August 1 parameter boundary — verified locally.
• Direct August 2026 calculations — $780 weekly-rate benefit and modeled employment activity eligibility verified.
• No partner API contract tests changed.