This subpart describes Fannie Mae's requirements for pooling mortgages that will serve
as the underlying asset for MBS, which includes UMBS. It includes Fannie Mae's MBS
program parameters and other information regarding MBS commitments, guaranty and buyup
and buydown fees, pooling loans into fixed-rate and ARM MBS and Fannie Majors, and
delivering and trading MBS and UMBS.
C3-1: MBS Program Overview
This chapter provides basic information on Fannie Mae’s MBS program and the lender’s
responsibilities associated with pooling loans into MBS, which includes UMBS.
C3-2: MBS Securitization Process
This chapter provides information on the MBS securitization process, including loan
parameters, transaction types, guaranty fees, buyups and buydowns, servicing fees,
pricing, and funding.
C3-3: MBS Guaranty Fees and Guaranty Fee Buyups and Buydowns
Lenders must pay Fannie Mae a guaranty fee remittance each month as compensation for
the lender’s right to participate in the MBS program. This chapter provides information
on guaranty fees and the requirements associated with buying the fee up or down.
C3-4: Pooling Loans into Fixed-Rate MBS
Lenders can pool mortgages into one of two types of MBS: fixed-rate MBS and ARM MBS.
This chapter provides information on pooling loans into fixed-rate MBS, which includes
C3-5: Pooling Loans into ARM MBS
There are two primary types of ARM MBS pools with weighted-average coupons, also called
ARM Flex pools. Accrual rates for ARM Flex pools may be based on a weighted-average
or a fixed MBS margin. This chapter provides information on pooling loans into ARM
C3-6: Pooling Loans into Fannie Majors
Lenders can pool mortgages into two types of MBS, which includes UMBS: Single-Issuer
and Fannie Majors. This chapter provides information on pooling loans into Fannie
C3-7: Delivering and Trading MBS
Lenders that sell their MBS rather than hold them as an investment may work with Fannie
Mae’s Capital Markets Pricing and Sales Desk to obtain a competitive price. In this
chapter, the steps entailed in delivering and trading MBS and the requirements associated
with these processes are provided.