Second lien mortgage loans are not assumable. If the servicer of a second lien mortgage loan is notified that a prospective purchaser wishes to assume a second lien mortgage loan, it must advise the servicer of the first lien mortgage loan, the borrower, and the proposed property purchaser that the second lien mortgage loan debt will be accelerated if the transfer takes place. This is true even if Fannie Mae holds the first lien mortgage loan and allows it to be assumed under its existing terms. If the servicer learns of the transfer after the fact, it should notify all parties that the second lien mortgage loan is in default and that steps will be taken to accelerate the debt. The servicer must then contact its Fannie Mae Servicing Representative (see F-4-03, List of Contacts) for approval of the acceleration.
See below for related Q&A's:
For more information please see: D1-4.2-02: Conventional Mortgage Loans That Include a Due- on-Sale (or Due-on-Transfer) Provision