If it has been properly reported on Form 1099-MISC in Box 3 "Other Income" then I suspect it will end up on Form 1040, Schedule 1, Line 8z.

I believe that employee 'earnings' paid in tax year after death are not subject to FICA (i.e., not earned) but Schedule C business earnings would be.  Check Publication 15 and 15-A, p. 45.