A Supervised Mortgagee is a financial institution that is a member of the Federal Reserve System (FRS) or whose accounts are insured by the Federal Deposit Insurance Corporation (FDIC) or the National Credit Union Administration (NCUA) – collectively referred to as “Federal Banking Agencies.”
A Nonsupervised Mortgagee is a lending institution that has as its principal activity the lending or investing of funds in real estate Mortgages, consumer installment notes or similar advances of credit, the purchase of consumer installment contracts, or from a directly related field. A directly related field is something directly related to the lending or investing of funds in real estate Mortgages, not simply actions relating to real estate in general.
For additional information see Handbook 4000.1 I.A.2. available at: https://www.hud.gov/program_offices/administration/hudclips/handbooks/hsgh