My wife decided not to pay back her loan from her 403b in 2019. She got a letter from her company saying she was considered at default which obviously means it's counted as taxable income. But the letter said it was deemed as a distribution effective January 2, 2020.  So it says she'll received a 1099R in January 2021.  So do I declare the income from her loan default for 2019 taxes, or do we wait until we receive the 1099R in 2021 and file it for 2020 taxes?