A tax-aware retirement Monte Carlo simulator

Deorbit Plan models a full retirement — federal and state taxes, Roth conversions, RMDs, Social Security timing, Medicare IRMAA, and ACA subsidies — across thousands of market paths, entirely in your browser. Your financial data never leaves the page: there is no account, no server, and nothing to upload. The interactive simulator loads on this page.

What it models

Progressive brackets and the interactions that actually drive a retirement tax bill — the ones flat “4% rule” calculators miss:

• Roth conversion ladders

  How the 5-year seasoning rule, gap years, and fill-the-bracket conversions turn pre-tax savings into tax-free money — and why looming RMDs put a deadline on it.

• The RMD tax bomb

  SECURE 2.0 start ages 73 and 75, the Uniform Lifetime Table, a worked example of forced income growing through your 80s, and how QCDs help defuse it.

• Medicare IRMAA surcharges

  Medicare premiums are set by your income from two years earlier — the 2026 tiers, why the boundaries are cliffs, and how a Roth conversion at 63 raises premiums at 65.

• The ACA subsidy cliff

  With the enhanced credits expired, subsidies end abruptly at 400% of the poverty level — how the cliff works, what counts as MAGI, and why $1 can cost thousands.

• The Social Security tax torpedo

  Provisional income, the 50% and 85% phase-in tiers, and why an IRA withdrawal in the wrong band is taxed at an effective 22.2% or 40.7% — plus how the spike ends.

• Why Monte Carlo, not one “number”

  Single-figure targets like 25× spending hide the thing that actually breaks retirements — the order of returns. What a Monte Carlo simulation does, what a success rate means, and what it doesn’t.

• 2026 tax brackets and standard deductions

  Reference tables for tax year 2026: the seven ordinary-income brackets, standard deductions, the 65+ additions and OBBBA senior deduction, and the 0%/15%/20% capital-gains thresholds — for single, MFJ, HoH, and MFS filers.

• 2026 401(k), IRA, and HSA limits

  Reference tables for 2026: the $24,500 deferral limit, $8,000 catch-up, the age-60–63 $11,250 super catch-up, the new Roth catch-up rule, IRA and Roth phase-outs, HSA/HDHP figures, and SIMPLE limits.

Browse all 49 guides in the Learn library →

How this site is made

The Learn library is not filler around a calculator — it is the point. Every article is written from primary sources (IRS publications and revenue procedures, Social Security and CMS regulations, the U.S. Code, and state revenue departments) and ends with a References list that links straight to them, so you can check any claim yourself. The same verified figures power both the articles and the simulator, and a standing review keeps them current as the law changes. Read the editorial method for exactly how that works.

Written and maintained by Jamie Rennick (a pen name — see About). Questions or corrections: help@deorbitplan.com.

Educational tool only — not financial, tax, or investment advice, and not a recommendation to buy, sell, or hold anything. Tax rules are simplified for a general audience; verify decisions that matter with a qualified professional.