If the excess contribution was though your employer, reported with code W in box 12 of your W-2, and TurboTax determined that you had an excess contribution after you completed the HDHP coverage questions, TurboTax will ask if you will be removing the entire excess contribution. Answering yes will cause TurboTax to automatically include Schedule 1 line 21 the amount of the returned excess.
If you personally contributed rather than contributing through your employer, TurboTax simply excludes the amount of the returned excess from Schedule 1 line 25.
TurboTax will only allow you to report the return of an actual excess contribution because only actual excess contributions are permitted to be returned. Entered properly, TurboTax will catch an excess contribution, even under the circumstances of a divorce. Are you sure you had an excess contribution; did TurboTax indicate an excess contribution when you entered the amount originally contributed (either with code W in box 12 of your W-2 or as a personal contribution)? Did you have any type of HDHP coverage on December 1, 2018?
