Sources
Each rules file cites the official publications it was built from. The list below is generated from those files, so it always matches the numbers on the site.
- IRS: Newsroom (tax inflation adjustments)
- IRS: Revenue Procedure 2025-32 (2026 tax rates)
- SSA: Contribution and benefit base
- IRS: 401(k) contribution limits
Rules US-2026 rev 1, reviewed November 12, 2026.