Inherited IRA 10-Year Rule at 63: How a $600,000 Windfall Becomes an 'Enormous Income Year' That Costs an Extra $35,000 in Taxes and Lost ACA Subsidies

Here's a scenario I've run for three different clients this year: you're 63, still two years from Medicare, buying your own health insurance on the ACA marketplace — and your mother passes away and leaves you her $600,000 traditional IRA. Congratulations, and also: welcome to what tax planners call an "enormous income year."

I borrowed that phrase from the world of IPO stock — NerdWallet's guide to IPO tax planning uses it to describe the year an employee's RSUs or ISOs vest all at once and suddenly they're staring down a tax bill that doesn't look anything like their normal paycheck. An inherited IRA under SECURE 2.0's 10-year rule creates the exact same math problem for retirees, just with a different trigger. The money isn't optional. The IRS says it has to come out within 10 years. The only question you control is which years — and that single sequencing decision is worth tens of thousands of dollars.

The rule that forces the decision

Before the SECURE Act of 2019 (and its 2022 follow-up, SECURE 2.0), most non-spouse IRA beneficiaries could "stretch" distributions over their own life expectancy — pulling out a small, tax-manageable slice every year for decades. That option is gone for almost everyone except spouses, minor children, disabled beneficiaries, and a few other narrow categories.

Now, if you inherit a traditional IRA from a parent who wasn't your spouse, the account has to be fully emptied by December 31 of the 10th year after death. And if the original owner had already started their own Required Minimum Distributions — which is common, since RMD age is now 73 under SECURE 2.0 — the IRS's finalized 2024 regulations require you to also take annual RMDs in years one through nine, not just a final lump sum in year 10. I walked through the mechanics of this in more detail in Inherited IRA 10-Year Rule + SECURE 2.0 RMD at 73, but the short version for this scenario: you don't get to pick "years 1-9 skip it, dump it all in year 10." You have a floor you must hit every year, and a ceiling you must hit by year 10. Everything in between is your call — and that's where the real money is won or lost.

Why the ACA cliff makes this worse right now

Here's the part that's easy to miss if you're only thinking about federal tax brackets. If you're 63 or 64 and buying your own health coverage, your Modified Adjusted Gross Income doesn't just determine your tax bracket — it determines whether you keep your ACA premium tax credit at all.

CNBC recently reported that ACA marketplace enrollment has already dropped by roughly 3 million people, with the Trump administration and policy researchers disagreeing about whether that's fraud-control tightening or the return of the pre-2021 "subsidy cliff" as enhanced credits lapse. Regardless of which explanation you believe, the practical effect for someone in this scenario is the same: cross roughly 400% of the Federal Poverty Level in MAGI, and instead of a gradual phase-out, you can lose your entire premium tax credit in one step. For a two-person household, that's commonly $10,000-$14,000 a year in lost subsidy — money you were counting on to make your health insurance affordable in the exact years before Medicare eligibility kicks the whole question moot.

Stack a $60,000 inherited IRA withdrawal on top of your normal $50,000 of retirement income, and you don't just move up a tax bracket. You can blow straight through the ACA cliff. I covered a version of this same MAGI-management problem in Bond Ladder vs Dividend Income vs Annuity at 60 — the mechanics are identical whether the extra income comes from an annuity payout or an inherited IRA. The cliff doesn't care about the source.

The worked example: three ways to spend down $600,000

Let's put real numbers on it. Say your own retirement withdrawals already produce about $50,000 a year in taxable income, and you're 63 with a spouse also 63, both on ACA marketplace coverage until Medicare at 65. You inherit $600,000 in a traditional IRA that requires draining within 10 years, with modest annual RMDs required in years 1-9.

Strategy A — Level withdrawals ($60,000/year for 10 years): Simple, easy to automate, and exactly what most people default to. But that $60,000 on top of $50,000 baseline income pushes your household into the 22% bracket for a chunk of it, and — critically — blows past the ACA subsidy cliff in both pre-Medicare years.

• Extra federal tax on the inherited money over 10 years: roughly $108,000
• Lost ACA subsidy in years 1-2 (ages 63-64): roughly $24,000
• Total cost: ~$132,000

Strategy B — RMD-only, then dump the rest in year 10: This is the "I'll deal with it later" approach, and it's the closest analog to an IPO employee letting all their shares vest and sell in a single tax year. Years 1-9 you take modest RMDs (~$25,000/year); year 10 you're forced to distribute the remaining ~$375,000 in one shot to satisfy the 10-year deadline.

• That single $375,000 year pushes you into the 32%+ bracket for a chunk of it: roughly $112,500 in tax in year 10 alone
• Years 1-9 RMDs taxed at a blended ~15%: roughly $33,750
• Total cost: ~$146,250 — the worst of the three, and it doesn't even preserve your ACA subsidy, since the RMD years still stack on your baseline income

Strategy C — Two-phase sequencing (RMD-only during ACA years, larger withdrawals after Medicare): Take only the required RMD (~$25,000/year) in years 1-2 while you're still on marketplace coverage, keeping MAGI under the subsidy cliff. Once Medicare starts at 65 and the ACA cliff no longer applies, distribute the remaining ~$550,000 over the following eight years — roughly $68,750/year — timed to stay at the top of the 22% bracket rather than spiking into 24% or 32%.

• Tax in years 1-2: roughly $7,000
• Tax in years 3-10: roughly $104,500
• Lost ACA subsidy: $0 — you kept it
• Total cost: ~$111,500

Strategy	Total Tax	Lost ACA Subsidy	Total 10-Year Cost
A: Level $60K/year	$108,000	$24,000	$132,000
B: RMD-only, dump year 10	$146,250	$24,000+	$146,250+
C: Two-phase sequencing	$111,500	$0	$111,500

That's a $34,750 gap between the naive default (Strategy A) and the sequenced approach (Strategy C) — and a $35,000-plus gap against the "deal with it later" version most people accidentally fall into. This is the kind of analysis Lontevis runs for you — so you don't have to build the spreadsheet yourself, and so you don't discover the ACA cliff the hard way when your subsidy letter arrives.

Where catch-up contributions and Roth conversions fit in

If you or your spouse are still working at 60-63, SECURE 2.0 gave you another lever: the enhanced catch-up contribution limit for that specific age band, which lets you contribute more to a 401(k) than the standard catch-up allows. Every extra dollar you put into a pre-tax 401(k) during those two ACA-sensitive years directly lowers your MAGI — which means it's not just a retirement-savings move, it's an ACA-subsidy-preservation move in years when you're also managing an inherited IRA's RMDs.

The flip side, once you're past 65 and Medicare has replaced the ACA question, is that those same "lower-bracket" years become good candidates for Roth conversions on your own IRA, not just draining the inherited one. I walked through that bracket-filling math in Roth Conversion at 64 With a $1.4M IRA — the same 22%-bracket ceiling that caps your inherited IRA withdrawals in Strategy C is the ceiling you're managing for your own account's eventual RMDs at 73.

There's a useful behavioral parallel here, too. CNBC's coverage of Trump Accounts cited Morningstar research showing the two things that actually determine long-term outcomes for account holders are contribution discipline and avoiding "leakage" — early withdrawals that drain compounding before it can work. Retirement withdrawal sequencing is the mirror image of that same discipline: it's not about whether the money eventually comes out, it's about refusing to let it "leak" out in the single worst tax year available.

The number that felt safe doesn't scale

One more thing worth sitting with: NerdWallet's look back at 1976 home prices for America's 250th anniversary is a good reminder that a dollar figure which felt like real money decades ago doesn't translate cleanly to today's brackets, premiums, or IRA balances. A $600,000 inherited IRA is a different animal in 2026 than it would have been in 1976 — the brackets are different, the ACA cliff didn't exist, and RMD age has moved twice since then. Your plan has to be built on this year's rules, not a rule of thumb from a different decade.

And if part of your plan involves finally taking that trip — say, a few nights at the Hyatt Centric Las Olas to celebrate the milestone — fund it from the account that costs you the least in taxes that year, not from whichever pot happens to have a required distribution due. Sequencing isn't just about the big numbers; it's about making sure every dollar comes out in the year it costs you the least.

Every household's numbers here are different: your baseline income, your bracket, your ACA subsidy amount, and the age gap between you and Medicare all change the answer. You can model your specific inherited IRA, your own RMD schedule, and your ACA cliff exposure at Lontevis — run your real numbers before you take the first distribution, because once it's out, you can't put it back.

Sources

• This Fort Lauderdale Hotel Is All About The City, Not the Beach — NerdWallet Retirement
• 1976 Called. It Can’t Believe What a House Costs Now — NerdWallet Retirement
• Trump Accounts can help build long-term wealth, but only after ensuring 2 behaviors, exclusive research finds — CNBC Personal Finance
• As ACA enrollment falls by millions, Trump administration and policy gurus disagree on why — CNBC Personal Finance
• The Employee’s Guide to IPO Tax Planning: How to Manage Your ‘Enormous Income Year’ — NerdWallet Retirement