Deductions & credits

First, be sure that you have indicated that your Schedule C business has employees.  Then, if you are using the Home and Business version of TurboTax, follow these steps:

1. While working in your Schedule C, click Update beside Business Expenses > Other Common Business Expenses.
2. Find Employee Expenses in the list and click Start or Update.
3. Click Start or Update beside Pension Plan Startup Costs.
4. Enter an amount for your startup costs.
5. Answer the questions about the number of employees and providing an auto-enrollment option.
6. Answer the question about whether your plan qualifies for the Pension Startup Credit.
7. Click Continue to exit this section.

Next, navigate away from your Schedule C and go back to the Business tab at the top of the screen.  Then, follow these steps:

1. Scroll to the Less Common Business Situations at the bottom of the screen.
2. Click Start or Update beside Business Credits.
3. Click Start or Update beside Pension Plans - Startup Costs, Auto-Enrollment...
4. Go through any questions to complete Form 8881 which is now part of your return.

If you are using a version other than Home and Business, the steps are similar except there is no Business tab at the top of the screen.  You will navigate to Wages and Income > Business Items > Business Deductions and Credits > Other Business Credits > Pension Plans - Startup Costs... for the input required for Form 8881.

@ramen dog