My father passed away last year and owed backed taxes. He didn't have an estate but he did have a retirement fund. My siblings and I are the beneficiares and was wondering if we have to pay his back taxes?

Did he owe more then his last tax return? If so the estate is liable for debts before any benefit is paid out.

Did he owe more then his last tax return? If so the estate is liable for debts before any benefit is paid out.

There was no estate. Yes I believe he owes more then his last tax return

Yes, he DOES have an estate. It is the retirement fund, and you MUST use those assets to settle any past tax bill (federal and state) before YOU can access that money.