In more detail
The amount is the account balance on 31 December of the previous year divided by a life-expectancy divisor from an official table; the divisor falls each year, so the required share rises with age. Under current US law the starting age is 73 for people born from 1951 to 1959 and 75 for those born in 1960 or later. The first RMD can be delayed to 1 April of the following year, which means taking two in that year. Roth IRAs need no RMDs during the owner's lifetime. The starting age and tables are set by law and change, so check current rules.
Why it matters
Missing an RMD triggers an excise tax of 25% of the shortfall, reduced to 10% if corrected promptly. The withdrawals are taxed as income, so large RMDs can push you into a higher bracket.
Example
Under the Uniform Lifetime Table in use since 2022, the divisor at age 73 is 26.5 and at 74 is 25.5:
- Age 73, balance $500,000:
500,000 / 26.5= $18,867.92 - Age 74, balance $510,000:
510,000 / 25.5= $20,000.00