In addition to traditional IRAs, simplified employee pension (SEP) IRAs and SIMPLE IRAs are subject to the RMD rules.
Roth IRAs, however, are not subject to these rules while you are alive. Although you are not required to take any distributions from your Roth IRAs during your lifetime, your beneficiary will generally be required to take distributions from the Roth IRA after your death.
Employer-sponsored retirement plans that are subject to the RMD rules include qualified pension plans, qualified stock bonus plans, and qualified profit-sharing plans, including 401(k) plans. Section 457(b) plans and Section 403(b) plans are also generally subject to these rules.
If you are uncertain whether the RMD rules apply to your employer-sponsored plan, you should consult your plan administrator or a tax professional.