still waiting x amended SSA1099

You have a couple of options.

You can extend your tax return and pay any taxes due by July 15, 2020.

You can file an extension within the program itself.

1. Log back into your TurboTax account and go to the federal section
2. Select Other Tax Situations at the top of the screen
3. Scroll down to Other Tax Forms
4. Select File an Extension
5. Proceed to answer the questions and follow the prompts to file your extension and make your tax payments

Extension requests in downloaded software

Extension requests using the online software

Your other option is to go ahead and file your tax return with the tax forms as you have them currently.  If they issue you a corrected 1099-SSA, you can amend your return as soon as they do. 

How to amend my return?

Otherwise, there is a chance they may not issue you another form until 2020. If that happens, your 2019 tax return will be fine as prepared and the repayments will be picked up on your 2020 tax return.