Dear Liz: You recently answered a reader who wondered whether he could delay mandatory distributions from his traditional IRA because he was still working. You said correctly that he could delay taking required minimum distributions from a 401(k) but not an IRA. But as long as the questioner is working full time and meets the other tests, he could contribute to a Roth IRA. That would allow him to re-invest part or all of the required distribution. Tax would have to be paid on the distribution, but the money could continue to be invested in an account that isn’t taxed on the earnings annually.

Answer: That’s an excellent point. Withdrawals from IRAs, SEPs, SIMPLE IRAs and SARSEPS typically must begin after age 701/2. The required minimum distribution each year is calculated by dividing the IRA account balance as of Dec. 31 of the prior year by the applicable distribution period or life expectancy. (Tables for calculating these figures can be found in Appendix C of IRS Publication 590, Individual Retirement Arrangements.)

Anyone who has earned income, however, may still contribute to a Roth IRA even after mandatory withdrawals have begun, as long as he or she doesn’t earn too much. (The ability to contribute to a Roth begins to phase out once modified adjusted gross income exceeds $112,000 for singles and $178,000 for married couples.) There are no required minimum distribution rules for Roth IRAs during the owner’s lifetime. As you noted, the contributor still has to pay tax on the withdrawal, but in a Roth IRA it could continue to grow tax free.