Husbands grandparents died 10 plus years ago his parents pay all property taxes who owns property?

That depends on whether the last surviving grandparent had a will. If the real estate was devised by will, the will must be probated in order for title to pass to the heirs legally. You can check the records of the probate court to determine if a will was probated for either grandparent. If there was no will the property would descend to the heirs-at-law under the state laws of intestacy. Generally, the heirs-at-law are the children of the decedent. You can check the laws of your state at the related question link provided below.