Yes. Even though you are required to start drawing down the account, you can continue to add to it through deductible contributions as long as you have net earnings from self-employment. However, you can no longer contribute to a traditional IRA if you had otherwise been able to do so; no contribution is allowed for the year in which you turn age 70-1/2 or any later year. There is no age limit for making Roth IRA contributions as long as you continue to have earned income.
Retirement plan set up by a self-employed person, providing tax-deductible contributions, tax-free income accumulations until withdrawal, and favorable averaging for qualifying lump-sum distributions.