I am so sorry for your loss.  You have given a whole lot of scenarios here and the particualrs  - Will or trust, revocable or irrevocable - matter in order to give any guidance.  There are some generalities that may help.  First, an irrevocable trust gives little protection from creditors.  That is because the settlor can revoke the trust at any time. An irrevocable trust can indeed protect the assets from the IRS but that is not tosay that depending on when the tranfer occurred and the lien occured the IRS would not try and set the transfer aside. Medical bills and creditors would also follow here.  If there is a Will and a trust then it porbably a "pour over will" to fund the trust with those assets if they were not properly placed in to the trust in the first place.  Please get help here.  Good luck.