Once you hit a certain age, the IRS stops letting your traditional retirement accounts grow tax-deferred forever — you’re required to start withdrawing a minimum amount each year, whether you need the money or not. These are Required Minimum Distributions (RMDs), and the rules around them have changed more than once in recent years, which is exactly why outdated advice about them is so common.
The age itself has moved. It used to be 70½, then 72, and current law has it at 73 (scheduled to move to 75 for people born in 1960 or later, under current law — though tax law in this area has changed before and could change again). The starting age depends entirely on your birth year, so don’t assume a number you read somewhere still applies to your specific situation without checking current rules.
Which accounts are actually subject to RMDs: traditional IRAs, SEP and SIMPLE IRAs, and traditional 401(k)/403(b) plans. Roth IRAs are not subject to RMDs during the original owner’s lifetime — one of the real, lasting advantages of Roth accounts. Roth 401(k)s used to require RMDs (a quirk that surprised a lot of people), but recent law changed that too, aligning them with Roth IRAs.
How the amount is actually calculated: your RMD isn’t an arbitrary number — it’s your account balance as of December 31 of the prior year, divided by a life expectancy factor from an IRS table that changes each year as you age. Multiple traditional IRAs can be combined and withdrawn from any one (or combination) of them to satisfy the total RMD, but 401(k)s generally each require their own separate RMD calculation and withdrawal unless specific rules allow otherwise.
The penalty for missing one is real, but it’s smaller than it used to be. The excise tax for a missed or shortfall RMD was cut from 50% to 25% of the amount not withdrawn under recent law, and can drop further to 10% if you correct the mistake within a defined correction window. That’s still a meaningful penalty on money that was supposed to come out anyway — and unlike some tax situations, “I didn’t know” doesn’t exempt you from it, though the IRS does have a process to request a full waiver for a genuine, reasonable-cause error, corrected promptly.
The first-year exception that trips people up: you technically have until April 1 of the year after you turn RMD age to take your first RMD. That sounds like extra flexibility, but taking that option means you’ll owe two RMDs in that following calendar year (the delayed one plus that year’s regular one) — which can push you into a meaningfully higher tax bracket for that single year. Running the numbers on whether delaying actually helps, rather than assuming it automatically does, is worth the time before deciding.
The planning angle worth knowing: if you’re doing Roth conversions in the years before RMD age specifically to shrink your future RMDs (a strategy worth its own separate discussion), the RMD calculation only cares about your traditional-account balance as of the prior year-end — so the timing and size of conversions in earlier years directly determines how large your eventual RMDs will be.