One withdrawal, three taxes

You've probably heard the advice for age 73: "just take the required minimum and pay the tax on it." Here's the honest problem with that — it treats the RMD like a bill, when it's actually a trigger. Your Required Minimum Distribution is ordinary income, and that income quietly re-prices three other things the same year: it can make up to 85% of your Social Security taxable, it sets your Medicare premium two years later, and it creeps your tax bracket. Advisors call the pile-up the tax torpedo, and the RMD is what fires it. Below: what the RMD is, how each part of the torpedo works, and three legal ways to soften it.

First, what an RMD actually is

For decades the government lets your traditional IRA and 401(k) grow tax-deferred — you never paid tax on that money going in. The Required Minimum Distribution is the government finally collecting: starting at a set age, it forces you to withdraw a minimum amount every year, whether you need the cash or not, and that withdrawal is taxed as ordinary income. You can't leave it growing untaxed forever. The start age is 73 if you were born 1951–1959, and 75 if you were born 1960 or later (SECURE 2.0). Say "73 or 75, depending on your birth year" — there is no single universal age.

It's not a bill — it's a trigger

Here's the shift that matters. The tax on the RMD itself is the small, obvious part. The expensive part is what the extra income does downstream. Because the RMD raises your income for the year, it can push you over invisible lines that re-price your Social Security tax, your Medicare premium, and your bracket — all at once. That cascade is the torpedo. Miss it, and you optimize the one visible tax while three hidden ones go off behind it.

Torpedo 1: up to 85% of your Social Security becomes taxable

Social Security isn't automatically taxed — it depends on your "combined income" (your adjusted gross income plus nontaxable interest plus half your benefits). Cross the IRS thresholds and a rising share of your benefits becomes taxable, up to a maximum of 85%. As a rule of thumb, the 85% tier begins around $34,000 of combined income for a single filer and $44,000 for a married couple filing jointly. A large RMD is exactly the kind of income that pushes combined income over those lines — so the forced withdrawal doesn't just get taxed itself, it drags your benefits into the tax base too.

Torpedo 2: your Medicare premium spikes — two years later

This is the one that surprises people, because the bill arrives late. The income on this year's tax return sets your Medicare Part B and Part D IRMAA surcharge two years later. And IRMAA is a cliff, not a ramp: go $1 over a bracket line and the entire higher surcharge applies. So a big RMD in a given year can quietly raise your Medicare premiums two years out. If a genuine life-changing event caused it, you can ask Social Security to reconsider with Form SSA-44 — but an RMD by itself isn't a qualifying event, so the better move is to avoid tripping the line in the first place.

Torpedo 3: bracket creep

The third hit is the simplest: stack a large RMD on top of your other income and part of it can spill into the next tax bracket, so the last dollars are taxed at a higher marginal rate. On its own it's the mildest of the three — but combined with the Social Security tax and the IRMAA cliff, all landing the same year, the three together are what earns the name "torpedo."

The April 1 trap: two RMDs in one year

You're allowed to delay your very first RMD to April 1 of the year after you turn 73. It sounds like a break. It's usually a trap — because you then have to take your second RMD by December 31 of that same year, so two RMDs land in one calendar year. Doubling the income in a single year is the fastest way to fire all three torpedoes at once. Unless there's a specific reason, take your first RMD in the year you turn 73 and keep the income spread out.

The penalty got smaller — but the torpedo didn't

If you skip an RMD, the IRS excise tax used to be a brutal 50% of the amount you should have taken. SECURE 2.0 cut it to 25%, and to 10% if you correct it within the correction window. Good news — but don't let it distract you. The penalty was never the real cost. The real cost is the torpedo that goes off every year you do take the RMD without planning for the cascade.

Lever 1: the QCD (give it straight from your IRA)

The Qualified Charitable Distribution is the cleanest tool. If you're 70½ or older, you can send money directly from your IRA to a qualified charity. It counts toward your RMD, and — this is the key — it's excluded from your income entirely. Because it never lands in your AGI, it doesn't feed the Social Security tax or the IRMAA cliff. The annual limit was about $108,000 for 2025 (inflation-indexed; confirm the current year's figure). If you give to charity anyway, doing it as a QCD instead of writing a check is often the single best torpedo-softener.

Lever 2: Roth conversions before 73

The torpedo is sized by how big your traditional balance is when RMDs begin. So the years before 73 — especially any low-income window after you retire but before RMDs and (for some) before Social Security — are the time to convert some traditional IRA money to Roth. You pay tax now, at today's rate, to shrink the future traditional balance. Smaller balance later means smaller RMDs, which means a weaker torpedo. Whether it's worth it depends on your bracket now vs later, your heirs, and cash to pay the conversion tax — so this one is genuinely situational.

Lever 3: take the first RMD on time

The simplest lever costs nothing: don't defer your first RMD to April 1. Take it in the year you turn 73 so you never stack two RMDs into one calendar year. It's the easiest way to keep the income — and the torpedo — spread out.

One exception worth knowing: still working at 73

If you're still employed at 73 or 75 and you do not own more than 5% of the company, you can generally delay RMDs from that current employer's 401(k) or 403(b) until April 1 after you actually retire. It applies only to that specific plan — your IRAs and old 401(k)s still have RMDs on schedule. Confirm the details for your own plan at irs.gov.

What to check this week

• Find your RMD start age — 73 or 75 by birth year — and, if you're already there, whether you deferred your first one to April 1 (the double-RMD trap).
• Estimate whether your RMD pushes your combined income over the 85% Social Security line or an IRMAA bracket — those are the two expensive lines.
• If you give to charity, ask whether a QCD fits. If you have a low-income year before 73, ask whether a Roth conversion fits. Both are situational — that's what a professional is for.

The RMD isn't the bill you should be watching. The cascade behind it is. Check the rule, not the slogan.

Educational only

This is educational only — not financial, tax, or investment advice. RMD ages, thresholds, penalties, and QCD limits change, and whether a Roth conversion or QCD helps depends entirely on your own bracket, accounts, charitable intent, and heirs. The dollar figures here are illustrative; confirm your own numbers at irs.gov, ssa.gov, and medicare.gov, or with a qualified professional who can look at your full return before you act.

Sources

• IRS — Required Minimum Distributions (RMDs) (start age 73/75; the April 1 first-year rule)
• IRS — RMD FAQs (the 50%→25%→10% penalty; still-working exception)
• IRS — Publication 915 & SSA — Income Taxes and Your Social Security Benefit (up to 85% taxable; the thresholds)
• SSA/Medicare — Medicare Premiums: Rules for Higher-Income Beneficiaries (IRMAA) & Form SSA-44 (the two-year lag; the appeal)
• IRS — Qualified Charitable Distributions (70½+, counts toward the RMD, excluded from income)