In TurboTax, you can amend your state return without filing an amendment for your federal. Please check the link below for instruction on how to amend your state return.
I need to amend my state return - TurboTax
To adjust the amount of state tax withheld you need to revisit the 1099-R in the federal return:
- Select Federal from the left menu
- Go to Wages and Income then Income and expenses.
- Scroll down to Retirement plans and Social Security
- Scroll down to IRA, 401K, Pension Plans (1099-R) and click Edit.
- Select Edit next to the 1099-R