Explanations
How retirement tax systems actually work.
Clear explanations of Roth conversions, tax brackets, IRMAA, and long-term tradeoffs — written to help you understand why outcomes change, not just what the numbers are.
If this feels confusing, that’s normal — these systems were not designed to be intuitive.
Educational explanations only. Simulations, not advice.
Core topics
Roth Conversions
What a Roth conversion is, how it is taxed, and when it may or may not make sense.
View →Tax Brackets & Income
How marginal brackets work, what “room left” means, and why timing matters.
View →IRMAA & Medicare
How Medicare premiums are calculated and why small income changes can have large effects.
View →Recommended reading
How RothMax Calculates Taxes
A step-by-step explanation of how ordinary income, capital gains, and conversions are modeled.
Read →What “Room Left in Your Bracket” Actually Means
Why marginal brackets matter and how Roth conversions interact with them.
Read →IRMAA: Why $1 Can Matter
How Medicare premium cliffs work and why small income changes have outsized effects.
Read →Methodology & transparency
These explanations are grounded in current U.S. federal tax law (2025), simplified where necessary, and explicit about assumptions.
We do not predict future tax law, investment returns, or personal outcomes. We show how systems behave under stated conditions.
Want to see how this applies to your own numbers?