My dad and father in law passed away in 2016 and they both were receiving social security. How do I need to file?

[Phillip1 · Accepted solution]

They may need to file final form 1040 individual income tax returns.

If there is income, they will need to file a final individual income tax return using the same filing status they would have regularly used. (See Deceased Persons from the IRS)

Whether your father and father-in-law need to file depends on whether they have income from sources other than Social Security. If Social Security is their only source of income, they would not be required to file a final tax return because their income would not be taxable (Social Security income is only taxable if the taxpayer has income from other sources).

If there was income from other sources (like retirement accounts reporting on form 1099-R) they should file a tax return using the best filing status for their situations.

They may also need to file an estate income tax return on form 1041. See this site for an explanation of this situation.