Once you reach age 73, you're required to begin withdrawing funds from tax-deferred accounts like a 401(k), 403(b), and traditional IRA. These are called required minimum distributions (RMDs) and are a way for the IRS to ensure it gets its tax money on the back end after providing the up-front tax break.

Let's take a look at how they work so you can avoid unnecessary penalties.

Someone writing in a notebook with cash and a calculator on table.

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Calculating your required minimum distribution (RMD)

The two factors that determine the amount of your RMD are your account balance(s) at the end of the previous year and the age you're turning in the current year. Knowing those, it's a two-step process to determine the minimum you must withdraw.

First, you look at the appropriate IRS-provided life expectancy table. The Uniform Lifetime Table applies to most retirees, while the Joint Life Expectancy Table applies if your sole beneficiary is your spouse and they're more than 10 years younger than you.

The number associated with your age on the applicable table is referred to as your life expectancy factor (LEF).

To see it in action, let's assume that you had $1 million in your account(s) to end 2024 and file taxes as single. Here's what your RMDs would be based on the latest figures. Note you have to take RMDs past age 80, but I only went up to 80 in this table for space reasons. 

Age Life Expectancy Factor Required Minimum Distribution
(balance divided by LEF)
73 26.5 $37,736
74 25.5 $39,216
75 24.6 $40,650
76 23.7 $42,194
77 22.9 $43,668
78 22.0 $45,455
79 21.1 $47,393
80 20.2 $49,505

Calculations by author. RMDs rounded to the nearest dollar.

Skipping an RMD could result in a penalty of 25% of the amount you failed to withdraw. If you correct your mistake and take your RMD within two years of the missed deadline, you can reduce the penalty to 10%.

In either case, you should make a diligent effort to avoid any penalties by staying up to date on your annual RMD obligations.