Freddie Mac's Primary Mortgage Market Survey (PMMS) surveys lenders each week on the rates and points for their most popular 30-year fixed-rate, 15-year fixed-rate, 5/1 hybrid amortizing adjustable-rate, and 1-year amortizing adjustable-rate mortgage products. The survey is based on first-lien prime conventional conforming mortgages with a loan-to-value of 80 percent. In addition, the adjustable-rate mortgage (ARM) products are indexed to U.S. Treasury yields and lenders are asked for both the initial coupon rate and points as well as the margin on the ARM products.

Since April 1971, Freddie Mac has surveyed lenders across the nation weekly to determine the average 30-year fixed-rate mortgage rate; in 1984, the 1-year ARM was added to the survey and the 15-year fixed-rate mortgage rate was included beginning in 1991. In January 2005, Freddie Mac added a 5/1 hybrid ARM series to the survey. Currently, about 125 lenders are surveyed each week and the mix of lender types-thrifts, credit unions, commercial banks and mortgage lending companies-is roughly proportional to the level of mortgage business that each type commands nationwide.

The survey is collected from Monday through Wednesday and the results are posted on Thursdays. Average rates and points (and margin for ARMs) for each product are reported for the nation and the five Freddie Mac regions. The PMMS results are published extensively in the media, used in several government agency reports, and many other industry-related publications. For example, the Federal Reserve Board includes the average 30-year rate on its list of Selected Interest Rates (Statistical Release H.15) as the measure of conventional mortgage rates.

The Primary Mortgage Market Survey has evolved into the foremost reliable, representative source of regional and national mortgage rate trends and is relied upon by the mortgage industry and the public in gauging market conditions and evaluating mortgage loan options.