Chapter 23: How RMDs Work
The worksheets from Chapter 23 of Fifty-Five. Type your own numbers, or try an example from the book to see how each one works.
The 2026 IRMAA table
Your MAGI from two years earlier picks your row. Type your MAGI into a calculator below and it finds the row for you. Or find it here and work the paper worksheet.
| Row | Individual return MAGI | Joint return MAGI | Part B premium, a month | Part D surcharge, a month |
|---|---|---|---|---|
| 1 | $109,000 or less | $218,000 or less | $202.90 | $0.00 |
| 2 | Over $109,000 up to $137,000 | Over $218,000 up to $274,000 | $284.10 | $14.50 |
| 3 | Over $137,000 up to $171,000 | Over $274,000 up to $342,000 | $405.80 | $37.50 |
| 4 | Over $171,000 up to $205,000 | Over $342,000 up to $410,000 | $527.50 | $60.40 |
| 5 | Over $205,000 and under $500,000 | Over $410,000 and under $750,000 | $649.20 | $83.30 |
| 6 | $500,000 or more | $750,000 or more | $689.90 | $91.00 |
Married filing separately, if you lived with your spouse at any time in the year
| Row | MAGI | Part B premium, a month | Part D surcharge, a month |
|---|---|---|---|
| 1 | $109,000 or less | $202.90 | $0.00 |
| 2 | Over $109,000 and under $391,000 | $649.20 | $83.30 |
| 3 | $391,000 or more | $689.90 | $91.00 |
MAGI here is your adjusted gross income plus any tax-exempt interest. The Part D surcharge is added to your plan's own premium. Each person on Medicare pays these amounts.
Where these figures come from: The 2026 Part B premium and Part D surcharge for every row of the IRMAA table, used when you type your MAGI (CMS, 2026 Medicare Parts A & B Premiums and Deductibles); The 2026 IRMAA income lines for individual, joint and married-filing-separately returns (SSA, Premiums: Rules for Higher-Income Beneficiaries). They are the 2026 amounts and they change every year.
Your RMD
The least you must take out of a pre-tax retirement account this year. It is last December 31's balance divided by the factor for your age.
The formula: Balance on December 31 of last year ÷ Factor for your age this year = This year's RMD
The calculator needs JavaScript. The paper worksheet below does not: it is the same arithmetic, written out.
The paper worksheet
Balance on December 31 $__________ ÷ Factor for your age ______ = This year's RMD $__________
If you have more than one IRA, do one line per IRA and add them up.
Walk through it, step by step
- Find each account's balance on December 31 of last year. It's on your year-end statement. Many companies also print the RMD for you.
- Figure out the age you reach on your birthday this year.
- Look up the factor for that age in the table in Chapter 23.
- Divide the balance by the factor.
- Repeat for each account. Add up the IRAs, and take that total from any of them. Take each 401(k)'s RMD from that 401(k).
- Take it out by December 31, or by April 1 of next year if it's your first one.
Check your answer
- Your RMD should be about 3.8% of your balance at 73, 4.1% at 75, 5% at 80, and 6.25% at 85.
- Use last year's December 31 balance, not today's. If the market moved a lot since then, your RMD won't reflect it, and that's correct.
- Compare with the amount your IRA company prints. If they don't match, ask them which balance and factor they used.
Figures this worksheet uses, and where they come from: Uniform Lifetime Table factors for ages 73 to 80, 82, 85, 88, 90 and 95, as printed in the Chapter 23 table (IRS, Internal Revenue Bulletin 2024-33, T.D. 10001).
How RMDs grow
What next year's balance and RMD look like if you take only the RMD and the account grows at a rate you pick. From 73 to 79 it also carries the table forward, one row a year, to age 80.
The formula: (Last year's balance − Last year's RMD) × (1 + growth rate) = This year's balance. Then This year's balance ÷ This year's factor = This year's RMD.
The calculator needs JavaScript. The paper worksheet below does not: it is the same arithmetic, written out.
The paper worksheet
Last year's balance $__________ − Last year's RMD $__________ = After the RMD $__________ × 1.______ (your growth rate) = This year's balance $__________
This year's balance $__________ ÷ This year's factor ______ = This year's RMD $__________
Walk through it, step by step
- Start with this year's December 31 balance and RMD, from the worksheet above.
- Subtract the RMD from the balance.
- Pick a growth rate. Write it as 1 plus the rate: 1.05 for 5%, 1.00 for none.
- Multiply. That's next year's balance.
- Look up next year's factor in the table.
- Divide next year's balance by that factor. That's next year's RMD.
- Repeat for as many years as you want to see. A simple table, one row per year, keeps it straight.
Check your answer
- If your growth rate is higher than your RMD percentage, your balance should still be rising. At 5% growth, that's true until about 79 or 80 in Jim's example.
- Your RMD should go up almost every year unless the market falls.
Figures this worksheet uses, and where they come from: Uniform Lifetime Table factors for ages 73 to 80, as printed in the Chapter 23 table (IRS, Internal Revenue Bulletin 2024-33, T.D. 10001).
Jim's two-in-one year
Your MAGI if you put off your first RMD until the next spring and take two in one year, next to your MAGI if you take one a year. It shows which row of the IRMAA table each one lands in.
The formula: First RMD + Second RMD + Your other income = MAGI in the year you take two
The calculator needs JavaScript. The paper worksheet below does not: it is the same arithmetic, written out.
The paper worksheet
First RMD $__________ + Second RMD $__________ + Other income, including taxable Social Security $__________ = MAGI $__________
Compare it with the IRMAA line for your filing status (Chapter 11).
Walk through it, step by step
- Figure your first RMD with the worksheet above.
- Figure your second RMD on a balance that hasn't had the first RMD taken out.
- Add your other income for that year, including taxable Social Security (Chapter 24).
- Add all three. That's the MAGI for the year you take two.
- Compare it with the IRMAA line. Then do the same for each year with one RMD apiece, and compare.
Check your answer
- Taking both in one year should raise that year's MAGI by roughly your first RMD.
- If waiting pushes you over an IRMAA line, or into a higher tax bracket, take the first RMD in the year you turn 73 (or 75).
Figures this worksheet uses, and where they come from: Uniform Lifetime Table factors for ages 73 to 76, and the ages RMDs start (73 or 75) (IRS, Internal Revenue Bulletin 2024-33, T.D. 10001); The 2026 Part B premium and Part D surcharge for every row of the IRMAA table, used when you type your MAGI (CMS, 2026 Medicare Parts A & B Premiums and Deductibles); The 2026 IRMAA income lines for individual, joint and married-filing-separately returns (SSA, Premiums: Rules for Higher-Income Beneficiaries).
The penalty for a missed RMD
The excise tax on an RMD you did not take in full: 25% of the amount you missed, or 10% if you take it and report it within the correction window.
The formula: Amount you should have taken − Amount you took = Shortfall. Shortfall × 25% = Penalty, or Shortfall × 10% if corrected in time.
The calculator needs JavaScript. The paper worksheet below does not: it is the same arithmetic, written out.
The paper worksheet
Required $__________ − Taken $__________ = Shortfall $__________ × 0.25 (or 0.10) = Penalty $__________
Walk through it, step by step
- Add up the RMDs for every account (the first worksheet in this chapter).
- Add up what you actually took out by December 31, from your Form 1099-R forms.
- Subtract. If the answer is zero or less, there's no penalty.
- If there's a shortfall, take it out now.
- Multiply the shortfall by 0.25, or by 0.10 if you correct it in time. File Form 5329, and ask for a waiver if the miss was a reasonable error.
Check your answer
- Your penalty can't be more than 25% of the shortfall.
- If you combined IRAs, check that the total you took covers all of them. Remember that each 401(k) must pay out its own RMD.
Figures this worksheet uses, and where they come from: Excise tax on a missed RMD: 25% of the shortfall, 10% if corrected in time (IRS, Retirement Plan and IRA Required Minimum Distributions FAQs).