Hi @w119 ,
If the financial institution reported your Post 1986 after tax contribution in Box 1 and Box 2, it might be that they did not track the after tax contributions (this contributions are usually reported in Box 5 ) separately and you might need to adjust the basis to determine the correct taxable distribution amounts.
Until all non-taxable money is returned to you, a portion of your benefit is paid to you tax-free each year. After all of your after-tax contributions are returned to you, your gross distribution and your taxable amounts will
be the same.
Please reach out to your financial institution. They will be able to let you if the reason they reported as taxable and if necessary help you figure out the correct basis.
Below are a few resources that might help you better understand this distributions : https://www.irs.gov/pub/irs-pdf/p575.pdf Page 17 .
Thank you and good luck!
