I got a 1099-R in the mail after I had already filed my taxes. Is there anything I can do now?

[DoninGA]

You will have to wait for the IRS to either Accept or Reject your filed federal tax return.
If the return is rejected you can make the necessary changes and e-file again.
If the return is accepted you will have to amend your original tax return. An amended return, Form 1040-X, can only be printed and mailed to the IRS if the original tax return was not e-filed. The IRS will take up to 20 weeks or longer to process an amended tax return.

Before starting to amend the tax return, wait for the tax refund to be received or the taxes due to be paid and processed by the IRS.

See this TurboTax support FAQ for amending a tax return - https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-return/amend-change-correct-return-a...

[SharonD007]

No, you cannot change your tax return after you submitted it electronically. You must wait until you receive an email informing you that it is accepted or rejected. Do not make any changes while your tax return is pending.

If your tax return is rejected, you may log in to TurboTax and make changes along with fixing the rejection. If your tax return is accepted, once it’s processed you can file an amendment through TurboTax using Form 1040-X.

For further information review the TurboTax articles: How to Correct Federal Tax Returns and Video: How to Amend Your Tax Return.