If you're still working, you can contribute the full amount of your salary deferral to a Roth 401 (k), regardless of your age. After you turn 72, federal tax law generally requires you to withdraw a minimum amount from your retirement savings plans each year. These withdrawals are called mandatory minimum distributions (RMDs). You can contribute to a traditional or Roth IRA, or even open an IRA Gold account, even if you participate in another retirement plan through your employer or company. However, you can still contribute to a Roth IRA and make cumulative contributions to a Roth or traditional IRA, regardless of your age.
Keep in mind that those who are 70 and a half years old or older and make contributions to a traditional IRA, a SIMPLE IRA, or an SEP IRA will continue to have to apply for an RMD, even if they are still working. In addition to the general contribution limit that applies to both Roth and traditional IRAs, your contribution to the Roth IRA may be limited depending on your reporting status and income.