As long as the individual requested a filing extension, the deadline to complete the rollover of the qualified plan loan offset is October 15, 2025. If no filing extension was requested by April 15, 2025, the rollover deadline has passed. The tax return doesn't have to be filed by October 15, although the filing would be late otherwise.
In TurboTax, enter each Form 1099-R exactly as received and, when asked, indicate that the money was moved to another retirement account and indicate the amount of the distribution that was rolled over. If the code M1 distribution is rolled over to a Roth IRA, that would be taxable but not subject to an early-distribution penalty. To make the rollover of the code M1 distribution nontaxable, it would need to be rolled over to a traditional IRA instead. It's also permissible to roll over the entire code B1 distribution (given that that distribution part of the offset distribution) to a Roth IRA, but only $6,122 of that distribution needs to be rolled over to avoid tax and early-distribution penalty on that distribution. In each case, the IRA custodian needs to be informed that these are rollovers of qualified plan loan offset distributions so that they can code the 2025 Form 5498 appropriately. The fact that the Form(s) 5498 will not be issued until next year has no bearing on how these distributions are reported on the 2024 tax return.
(Note that because code M would be a third code in box 7 of the distribution of a qualified plan loan offset from the designated Roth account and box 7 can only accommodate two codes, the instructions for Form 1099-R indicate that the code M is to be omitted from box 7.)
