ARM MBS Subtypes

Adjustable-rate (ARM) Fannie Mae MBS Subtypes are alphanumeric codes that identify ARM product characteristics such as index, initial fixed-rate period, rate and payment adjustment frequency and caps, convertibility, and other features.

The following files contain certain key features of adjustable-rate mortgages backing Fannie Mae MBS. These features constitute the particular subtype of an adjustable-rate Fannie Mae MBS pool identified in the matrix file. Subtypes are only applicable to adjustable-rate securities. The latest subtype definitions are available after 7 a.m. ET, and will include any new subtypes created the prior day.

Our consolidated listings of all Single-Family (SF) and Multifamily (MF) subtypes and attributes are available in .csv and .xls format. Please allow automatic updating when opening the .xls file with your spreadsheet application.

• MF_Consolidated_report.csv
• MF_Consolidated_report.xls
• SF_Consolidated_report.csv
• SF_Consolidated_report.xls

You may also select specific Single-Family ARM Fannie Mae MBS subtype groups, which are displayed by reference index in text format (.txt).