Actually, it's the responsibility of the beneficiaries to coordinate among themselves to complete the year-of-death RMD, not the responsibility of the IRA custodian. Absent such coordination meant to ensure that the RMD has been satisfied by some combination of distributions by beneficiaries, it's reasonable to consider that your portion of that responsibility has been satisfied by you taking a distribution to your proportionate share of the remaining RMD and that with respect to your tax return, you have received all of the RMD for 2023.
