My grandfather passed away and the union he belongs to sent money to my grandmother for funeral expenses. She had to provide them receipts to prove she used the majority of the funds for funeral expenses. They sent her a 1099-MISC, Box 3 for the funds. Is this considered taxable income?
I found this related question: https://ttlc.intuit.com/replies/5963424 but it didn't quite answer if the income is actually taxable.
Yes, because it wasn't a gift. However it was a reimbursement for the expenses paid* and it was received because of the service your grandfather provided as a union worker. If not, you would not have received a reimbursement from them.
The answer you cited above is the best resolution as long as you offset the income only to the extent it was used to pay for the funeral expenses. As noted in that answer, there is nothing to indicate this should be income, but the union believes they are required to report it which has likely not been done in the past. Follow the instructions below.