While the IRS requires RMD amounts to be calculated starting in the year you (or your spouse) turned 70 and ½ years old, an RMD amount is not shown on your 1099-R.
If you are 70 and ½ and older, TurboTax will ask several questions when entering your 1099-R information. The purpose of these questions is to help you determine if you have met the RMD criteria so that you can avoid the IRS penalty.
Note: Your 1099-R issuer is required to follow RMD rules and regulations, so if you received a distribution and you're at least 72 years young, you can be almost certain you received an RMD. Check with your plan administrator if you're still not sure.