Received a nonemployee compensation amount at retirement that was reported on 1099-NEC. Turbo tax wants to report this as a business. How do I turn off schedule C?

If the payment you received pertained to your former employment, your employer should have included it on your W-2 for your final year. 

If you did work for them as an independent contractor after your retirement, then the income would be correctly considered self-employment and reportable on Schedule C along with any deductible expenses.

To enter a payment that was incorrectly reported on Form 1099-NEC, you can go to Other Reportable Income. Delete the Form 1099-NEC entry that caused TurboTax to generate a Schedule C. The IRS information return matching programs will look for the amount to be accounted for on your return.

In TurboTax Online:

1. Go to Wages and Income
2. Scroll down to Less Common Income
3. Go to Miscellaneous Income
4. Select Other Reportable Income and follow the prompts. Enter a description of the reason for the payment.