@ojbyrne
Where in this procedure is it broken for you when using the TurboTax 2018 Mac software?
- Click on Federal Taxes (Personal using Home and Business)
- Click on Deductions and Credits
- Click on I'll choose what I work on (if shown)
- Scroll down to Estimates and Other Taxes Paid
- On Other Income Taxes, click on the start or update button
On the next screen select the type of extension payment made and click on the start or update button
