Thanks. Yes, I had seen IRS Publication 559. Although not exactly on point, the only relevant statement I found was "The decedent's income includible on the final return is generally determined as if the person were still alive except that the tax period is usually shorter because it ends on the date of death." I guess I could infer from that "person were still alive" as including the deceased person's SSN. The IRS was however very specific about NOT using the deceased indivdual's identifying number in the years AFTER his death.
There was also 'IRS Tax Tip 2023-51' : "Generally, the final individual income tax return of a deceased person is prepared and filed the same way as if the person were alive." References more than just 'income' and reinforces the inference to use the deceased person's SSN.
I guess my desire for more specificity from the IRS (RE using deceased SSN for the year of his death) is in vain.
