What "Lien Theory" Means for Property Owners
Arizona is what attorneys call a "lien theory" state. That distinction matters. In some states, signing a mortgage temporarily transfers legal title to the lender until the loan is repaid. Arizona does not work that way. When you sign a mortgage here, you keep full ownership. The lender simply holds a lien, a legal right to force a sale if the debt goes unpaid.
A mortgage is a lien upon everything that would pass by a grant of the property, but does not entitle the mortgagee to possession of the property unless authorized by the express terms of the mortgage.
A.R.S. § 33-703(A)This means you can live in the home, rent it, or transfer it into a living trust without the lender taking possession. The mortgage follows the property as a lien, but ownership stays with you.
After-Acquired Property and the Mortgage Lien
There is one less obvious piece of this statute worth noting. If the borrower acquires additional title interest in the property after signing the mortgage, that new interest is automatically covered by the existing mortgage lien.
Title acquired by the mortgagor subsequent to the execution of the mortgage inures to the mortgagee as security as if acquired before the execution.
A.R.S. § 33-703(B)In practical terms, this prevents a borrower from arguing that a later-acquired interest in the same property falls outside the mortgage. The lien covers the full ownership interest, whenever it was obtained. For families working through estate planning, this confirms that the mortgage lien remains intact regardless of changes in how title is held.
