What is the required minimum distribution once an IRA reaches maturity?
The minimum you must withdraw from your SEP/SIMPLE/traditional IRA (not a ROTH), or 401(k), profit-sharing, 403(b), or other defined contribution plan each year is called your Required Minimum Distribution (RMD).
Your RMD is due by 12/31 each year after the required beginning date. The first year usually has two distribution dates: April 1 and by 12/31 (for the year following the year you turn 70½). You can avoid including both of these in income in the same year if you take your first RMD withdrawal by 12/31 of the year you actually turn 70½.