"Required Minimum Distributions (RMDs) are mandatory withdrawals from your tax-deferred retirement accounts, such as 401(k)s and traditional IRAs, starting at a specific age. The age at which you must start taking RMDs is primarily determined by your age, not your employment status. However, if you're still working for the company that sponsors your 401(k), you generally don't have to take RMDs from that account. If you have multiple retirement accounts, you'll need to calculate and withdraw RMDs from each eligible account. Failing to take your full RMD can result in a significant penalty, typically 50% of the amount you should have withdrawn."