Updates
530A rules are young and still evolving — this log records every rule re-verification and site change, dated. Rules last verified 2026-07-12.
MCP server opened to every AI platform
Published to the official MCP registry (com.530amodel/calculator) with ChatGPT-compatible search/fetch tools, structured tool results, and platform setup guides for Claude, ChatGPT, Cursor, and agent APIs.
Live fund returns in the Advanced Model
New fund and historic-period dials set the return assumption from real market data (trailing 1/5/10-year annualized returns for the eligible funds), converted to after-inflation terms with the math shown.
New guides: glossary, withdrawals, timing, employer money, 530A vs 529
Five plain-English reference pages covering the questions families actually search, each grounded in the verified rules and linked to primary sources.
Security hardening
Strict Content-Security-Policy with per-build script hashes, HSTS, and per-IP rate limiting on all public endpoints.
Pledges & gifts feed
A tracked feed of reported 530A pledge programs, with human-reviewed entries you can model for your own child in one click — now also available as RSS.
Public API and MCP server
The calculator engine became free to call: JSON API with OpenAPI spec, and a read-only MCP server for AI assistants. No auth, nothing stored, attribution asked.
Rules verified against primary sources
Every figure re-checked against the statute, IRS Notice 2025-68, and the CRS overview. Unverifiable items (529 rollover, early-withdrawal penalty, cap indexing mechanics) remain explicitly flagged pending the expected March 2026 regulations.
530amodel.com launch
Free, privacy-first 530A calculator: instant projection widget, Advanced Model with seeded Monte-Carlo ranges, and cent-exact math cross-verified between two independent implementations.
Watching for the March 2026 Treasury regulations? They will settle the flagged items on the resources page; re-verifications land here first.