Sources we use
We rely on primary sources: Social Security Administration fact sheets, actuarial tables and program rules (POMS), IRS notices, revenue procedures and publications (590-A, 590-B, 560, 571), the Treasury regulations, CMS Medicare premium announcements, OPM retirement guidance and the Thrift Savings Plan. We do not use brokerage blogs, insurance sellers or other calculators as sources of fact.
How calculators are checked
Every calculator uses published, standard formulas. The code is covered by automated tests that check known answers (for example, the Social Security estimator reproduces the SSA actuaries' published benefit example to the dime, and the RMD calculator reproduces the worked examples in IRS Publication 590-B). We show the formula next to each tool so anyone can verify the result by hand.
What we will not publish
- Advice on when you personally should claim Social Security, which investments to buy or which annuity or Medicare plan to choose.
- Paid placements, affiliate links, lead forms or reviews written for a financial, insurance or annuity company.
- Claims we cannot support with a source.
Updates and corrections
Each page shows the date it was last updated. When the SSA, IRS, CMS or OPM publishes new figures (the Social Security COLA and wage base in October, the IRS plan limits in the fall, Medicare premiums in November), we update the engine, re-run the tests and update the affected pages. If you find an error, tell us through the contact page and we will review it and correct it.