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 format.

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

19_WSJ_1-year_LIBOR.txt
1__11th_District_Cost_of_Funds_Index.txt
25_WSJ_6-month_LIBOR.txt
29_WSJ_1-year_LIBOR.txt
2__1-year_CMT.txt
35_WSJ_6-month_LIBOR.txt
3__5-year_CMT.txt
49_Wkly_Auction_Avg_Yield-6mo_T_Bills.txt
4__6-month_Auction_Avg_Discount_Rate.txt
55_5-year_Treasury_Security_Weekly.txt
5_Freddie_Mac_Federal_Cost_of_Funds.txt
5__FHLB_Monthly_Median_Cost_of_Funds.txt
69_WSJ_1-year_LIBOR.txt
6__6-month_Auction_Avg_Investment_Rate.txt
75_1-year_CMT_weekly.txt
79_1-year_Weekly_CMT.txt
7__FHLB_Contract_Rate.txt
7__PRIMARY_MTG_MKT_SURVEY_PLUS_REPLACED_FHLB_CONTRACT_RATE.txt
85_30-DAY_AVERAGE_SOFR.txt
89_WSJ_Prime_CMT.txt
8__3-yr_CMT.txt
9__6-month_Auction_Average_Secondary_Market.txt
A9_Cum_Avg_of_Prev_12_mo_6-mo_Treasury.txt
A__1-year_CMT_Monthly.txt
B9_12-month_Average_of_1-year_CMT.txt
B__Monthly_Avg_of_6-mo_Wkly_Auct_Avg_Rates.txt
C9_1-year_Treasury_Security_Weekly.txt
E5_WSJ_1_year_LIBOR.txt
E9_3-year_CMT_Weekly.txt
E__2-year_CMT.txt
F9_5-year_CMT_Weekly.txt
F__10-year_CMT_Weekly_Average.txt
G__Wkly_Avg_of_Secndry_Mrkt_Rates_on_6-mo_CD.txt
H9_6-month_Weekly_Auction_Avg_Investment.txt
H__3-year_CMT_Monthly.txt
I__Monthly_Avg_Secondary_Mrkt_Rate_on_6-mo_CD.txt
J5_WSJ_1_Year_LIBOR.txt
J9_Auct_Avg_on_Ann_Dscnt_Basis_1-yr_T-bill.txt
K5_Cum_Avg_of_Prev_12_mo_1-yr_Treasury.txt
K9_GW_Financial_Avg_Deposit_Acct_Rate_COSI.txt
K__Wall_Street_Journal_6-month_LIBOR.txt
L9_Cum_Avg_of_Prev_12_mo_1_yr_CMT_Monthly.txt
L_Freddie_Mac_Federal_Cost_of_Funds_QTRLY.txt
L__Natl_Avg_COF_for_SAIF-insured_Inst.txt
M9_Freddie_Mac_Federal_Cost_of_Funds.txt
M9_Natl_Median_COF_for_SAIF-insured_Inst.txt
MF_Consolidated_report.csv
MF_Consolidated_report.xls
M_6-month_WSJ_LIBOR.txt
N5_WSJ-1YR-LIBOR.txt
N_12-month_Average_of_1-year_CMT.txt
O__Wall_Street_Journal_3-month_LIBOR.txt
P9_Wall_Street_Journal_1-year_LIBOR.txt
Q9_FHLMC_Fed_COF.txt
R9_Fannie_Mae_60-day_Required_Yield.txt
S9_Cum_Avg_of_26_wks_6-month_T-bill_Wkly_Avg.txt
SF_Consolidated_report.csv
SF_Consolidated_report.xls
T__5-year_CMT_Monthly_Average.txt
U5_WACHOVIA_COST_OF_SAVINGS_INDEX_(79).txt
U5_WACHOVIA_COST_OF_SAVINGS_INDEX_79.txt
U9_1-year_Weekly_CMT.txt
U__Wall_Street_Journal_1-month_LIBOR.txt
V5_1-year_Weekly_CMT.txt
V9_Natl_Avg_Contract_Mortgage_Rate.txt
V9_PRIMARY_MTG_MKT_SURVEY_PLUS_REPLACED_Natl_Avg_Contract_Mortgage_RT.txt
V__Cum_Avg_of_Previous_12_months_1-yr_CMT.txt
W5_1_year_Treas_Cum_Avg_Last_12_Months.txt
W_1-year_WSJ_LIBOR.txt
X9_1-year_Treasury_Security-weekly-rate.txt
Y5_Wells_Fargo_Cost_of_Savings_Monthly.txt
Y9_Golden_West_Fin_Cost_of_Deposits-CODI.txt
Z9_WSJ_1-year_LIBOR.txt
Z__12-month_Average_of_Monthly_1-yr_CMT.txt
snglix75.txt