I am filing for my deceased mother & I do not have her Form 1099-R or Form SSA-1099. How do I obtain those?

[VolvoGirl]

You get the SSA-1099 from Social Security.  How to get a copy of a SSA-1099

https://faq.ssa.gov/en-us/Topic/article/KA-01723

KA-01723 · Customer Self-Service

The 1099R comes from the plan.  Do you know what retirement she gets?  Who is her pension, 401K or IRA?  You have to ask them for another copy.  If you have her last year’s tax return and paperwork that should tell you what you need and who sent it.  Her bank account might have deposits from the payers.