Tax returns irs
Engage a CPA or enrolled agent; file final Form 1040 and consider Form 1041 for estates or trusts
Some steps differ by region inside the country.
Where
Their CPA or tax preparer, their own files, and the IRS directly using Form 4506-T.
How
Ask their CPA or tax preparer for copies of the last three years of returns.
Check their files and email, since preparers usually send a PDF copy each year.
Request transcripts from the IRS with Form 4506-T if no copies can be found.
Use the returns as a checklist of institutions, since every 1099 and K-1 identifies one.
What to bring
Their Social Security number
A certified copy of the death certificate
Letters testamentary and IRS Form 56
Sources
This is practical information, not legal, medical, or financial advice.