I got a 1099-R form after I filed my taxes

1. Wait until your original return has finished being processed by the IRS. How will you know? Well, if you are due a refund, then when you receive it, you know they are finished processing. If you are not due a refund, then wait at least at least 3 weeks to make sure that they are finished with it.
2. Amend your return through TurboTax, adding the new 1099-R information. For more information on the amendment process, please see the following:

Do not hold this form until next year.

Please see this video from TurboTax explaining the amendment process if you want to do it yourself - https://turbotax.intuit.com/tax-tools/tax-tips/IRS-Tax-Return/Video--How-to-Amend-Taxes-That-Are-Alr...

If you want to do the amendment through TurboTax, please read the article at this link - https://turbotax.intuit.com/tax-tools/tax-tips/IRS-Tax-Return/Amending-Your-Income-Tax-Return/INF120...

Normally, you would reopen the return and indicate that you want to amend the return, and then proceed through the interview.

Note: since most state returns are dependent on numbers from the federal return, if you have one or more state returns, you will probably have to amend the state returns as well.