"est of late parent

Does this go on the taxpayers return?"

I assume your title and that comment, is "est" = Estate. You need to know when the person died, and then the financial activity types each have their own events.

1099-R = Retirement. Retirement accounts typically have beneficiaries. That could be a pension, though, that dies with the decedent.

1099-Div is from investments. They can have beneficiaries. Or, it flowed to the Estate. And maybe this person had a trust that handles the estate and disburses it.

So, who was supposed to do what upon this person's death? Or, are we simply collecting paperwork and money somewhere and no one dealt with the responsibilities to wrap up the life upon the death?

Because until you know this, you don't know what to do with those forms. Maybe you are supposed to be preparing the dead person's final tax return. Or, an estate tax return. Or, a trust tax return.

We sure won't know.