Tax-deferred money cannot sit forever. From 73 or 75 — depending on when you were born — the IRS requires a withdrawal every year, taxed as income whether you need it or not.
Free to run.
How to use it
Enter the balance of every tax-deferred account. Traditional 403(b), 457(b), traditional IRA. Roth accounts are not subject to lifetime RMDs.
Give your year of birth. It sets the age withdrawals start — 73 or 75, depending on when you were born.
Use a realistic return. Growth between now and your start age decides how large the first required withdrawal is.
Set the tax rate you expect in retirement, not the one you pay now. A pension already fills the lower brackets.
This uses the IRS Uniform Lifetime Table. If your sole beneficiary is a spouse more than ten years younger, a different table applies and your required amount is lower.
see whether the account gets that big in the first place
Age
Balance
Required
% of balance
Est. tax
See every year, and the tax bill
Pro adds the full schedule to age 95 — balance, required amount, the share of the account it represents and the estimated tax — plus what is left at the end.
A required minimum distribution is not a withdrawal you choose — it is one the IRS requires, taxed as ordinary income whether or not you need the money. For most retirees that is merely annoying. For a teacher it can be expensive, because a pension already occupies the lower brackets before the withdrawal arrives, so the forced amount is taxed at the top of your range rather than the bottom.
The required share of the account rises every single year: about 4% at 75, over 6% at 85, near 10% at 95. A large tax-deferred balance therefore produces a rising taxable income exactly when most people expect their income to be falling.
What can be done about it
Withdraw in the gap years. Between retiring and the RMD age, taxable income is often at its lowest for decades. Voluntary withdrawals in those years come out at a lower rate than the forced ones later.
Consider Roth conversions in the same window — the same idea, with the tax paid deliberately at a rate you choose. Roth accounts are not subject to lifetime RMDs.
Qualified charitable distributions from an IRA can satisfy the requirement without adding to taxable income, if giving is already part of your plan.
Do not let the tail wag the dog. A large RMD is a symptom of a large balance. It is a better problem than the alternative.
Social Security Timing — the gap years before claiming are the same years worth withdrawing in.
State Tax Comparison — several states tax these withdrawals differently from pension income.
Educational estimates only, not tax advice. Divisors come from the IRS Uniform Lifetime Table in effect since 2022; confirm against IRS Publication 590-B, and check whether the joint-life table applies to you. Start ages changed under SECURE 2.0 and may change again.