IRA allocation model
The engine maps supported annual inputs to a Form 8606 planning worksheet using decimal arithmetic. The current authoritative form instructions are for 2025. The 2026 planning model uses the published year-specific contribution and federal tax data, with provisional form treatment until final instructions are verified.
Boundaries
Unsupported exceptions are flagged for review. State and local taxes are excluded; no state tax calculation is implemented. A tax payment estimate does not include every return interaction.
Change control
Source changes should be recorded with year, review date and regression evidence. Independent professional review is required before claiming filing-grade accuracy.