Make certain before you discard anything that there are no unclaimed credits on your parent’s tax accounts. Sometimes older people have a credit elect or estimated payments made to the next tax year. Their record keeping might not be very good and the estate might not be aware of them. The taxes are filed and processed and they money just sits there.
It might be several years before the IRS starts to send letters. If it has not been changed, the letters may go to the address of the deceased and might not get forwarded to the estate. You generally have 3 years to submit a claim for their refund and will probably not get it back after that time.
Well, it's been six years since she passed, and the estate return did get audited (which resulted in a reduction in valuation and the IRS sent us back $124K in over-payment). To conclude the audit, both us and the IRS signed a letter stating that that forever settled her estate as far as the IRS was concerned.
So at this point, all I'm concerned with is all her past personal returns. I suspect the chance of them causing trouble at this point is pretty slim, but who knows.