It stands for private label mortgage; a type of mortgage (mortgage loan) that is used by private entities (not government agencies) to back and issue non-agency mortgage-backed securities (non-agency MBS) . Private entities create and issue these securities to the public investors. Examples of private entities, that issue securities backed by private-label mortgages (non-agency mortgages), include banks, brokerage firms, and home constructing companies.

The non-agency MBS market offers mortgage financing to market players (individual mortgagors) that cannot meet the standards set for holding and investing in agency MBSs.