When someone passes away, and those handling the final arraignments actually do their job (usually the funeral home) the Social Security Administration is notified of their passing. In turn, the SSA notifies the IRS. The IRS then locks the SSN of the deceased person so it can't be used fraudently. One (of many) errors you will get when attempting to e-file a return with a locked SSN on it is "SSN LOCKED". When that happens, that's your indication that those who handled the final arrangements actually did their job. You have no choice but to print, sign and mail the return.
Sometimes, you might have to include the IRS Form 1310 with the mailed return if a refund is due on it. That form is not included in TurboTax. But you can print a blank one to file out and sign at https://www.irs.gov/pub/irs-pdf/f1310.pdf. Additionally, it may be necessary to include in your mailing any documentation that allows you to legally sign the return of a deceased person. Something like a court document appointing you as the administrator of the person's estate may suffice.
