About

bracketfilling.com is a free Roth conversion calculator focused on the interaction effects most other free tools skip: IRMAA cliffs with the 2-year MAGI lookback, ACA subsidy phase-outs with the restored 400% FPL cliff, Social Security taxation via the provisional income formula, NIIT thresholds, the OBBBA SALT cap, SECURE 2.0 RMD cohorts, and state income tax for all 51 jurisdictions. Every published page computes its numbers from the same engine the calculator runs; the prose cannot say one thing while the table says another, because both come from the same functions.

Who runs it

The site is built and maintained by Mario Bailey, a U.S. Air Force veteran with a professional background in banking and financial services. He is not a CPA, CFP, or enrolled agent, and the site does not pretend otherwise. The credibility model is different: no figure on this site rests on the author's say-so. Each one is computed by the open calculator engine from a primary source you can check, or cited directly to that source.

Where the numbers come from

The math layer is open source under src/calc/. Federal brackets and the standard deduction come from the annual IRS revenue procedure, IRMAA tiers from the CMS premium fact sheet, ACA poverty-line figures from the HHS guidelines under the IRC §36B vintage rule, and state rules from each state's revenue department or statute. Every tax-data file records its source URL and the date it was last verified (currently 2026-07-01). Data is refreshed each fall when the IRS and CMS publish the next year's figures, and a validation script cross-checks every new number against the prior year before anything ships. The methodology page documents each module, its statutory basis, and the known limitations.

How the site makes money

The calculator is free and stays free. Revenue comes from display ads on guide pages (never on the calculator itself) and an optional advisor-matching form shown after results for people who want a fiduciary to review their plan. Nothing on the site is paid placement, and no tax figure is influenced by any of it.

Your data

There are no accounts. Scenarios live entirely in the URL, so sharing a link reproduces the full calculation and nothing is stored server-side. Analytics run on Plausible, which uses no cookies and collects no personal data; details are in the privacy policy.

Corrections

Corrections, data issues, and questions are welcome through the contact form. A confirmed numeric error gets fixed in the data layer, which corrects every page that computed from it at the next build.

This is not tax advice. The calculator is a planning tool. For a Roth conversion strategy reviewed against your full situation, use a qualified fiduciary; the optional matching form below the calculator results exists for exactly that.