Q: Does a mortgage follow inheritance in PR and can you disclaim an inheritance in PR?

A: Signing as debtors makes them obligated on the loan. The rest of your question is confusing, because I think you are confused as to terms and concepts. If the property is owned solely by your uncle, which it would be if the property was titled as joint tenants with right of survivorship with your grandparents when they died, then upon his death the property would distribute to the persons named in his will (or heirs at law if he has no will), and those persons would take the property "subject to" the mortgage, but without personal liability on the mortgage (meaning, if they don't pay it, the lender can foreclose). If he owned the property as Tenants in Common with your grandparents, then he owns one-third of the property outright, plus whatever share your grandparents left him of the other two-thirds. If your mother and aunt also inherited an interest in the property from your grandparents, then that explains why your uncle needs their signatures on any new mortgage, since all titled owners must sign off on it. If the lender agrees, and your uncle qualifies alone for the new loan, your mother and aunt could sign to permit the recording of the lien securing the mortgage to the property, without signing personally on the loan. That's up to the lender to agree to, or refuse to lend the money. Anybody entitled to inherit under a will can disclaim all or any part of their inheritance if they so choose. No heir becomes personally liable for the debts of a deceased person, unless they are already personally liable on the debt. I do not understand your reference to "PR". Are you referring to "Personal Representative", or Puerto Rico? Either way I don't understand the reference.