I think I understand now. If I'm filing a paper tax return for last year, I should show the distribution and accrued interest (which is taxable in 2019) on Form 1, and attach an explanation stating that the distribution is the return of an excess contribution for 2019. The 1099-R that I receive next January should have the code P in Box 7, which means that the contribution was made for 2019 but returned in 2020, prior to the tax deadline. As long as I've shown and explained the distribution and paid the tax on the interest, I shouldn't have to file an amended return next year. Is this correct?
