Estimated Share of Outstanding U.S. Mortgages Below the Market Rate · %

## What this measures

The estimated share of U.S. residential mortgages outstanding at quarter end whose contract rate is below the market rate, the quarter's average Freddie Mac Primary Mortgage Market Survey 30-year fixed rate (fred_mortgage30). NMDB publishes whole-point rate buckets: buckets wholly below the market rate count in full, and the 3–3.99%, 4–4.99% or 5–5.99% bucket the market rate falls in counts in proportion, as if its loans were spread evenly across the point. A Palanor calculation. Q1 2013 to Q2 2026.

## Why it matters

The headline lock-in number: how many owners would pay more to move. It was small while rates sat near record lows and jumped once the market rate climbed past the rates most owners had locked in.

## How to read it

Q2 2026: at least 77.6% of outstanding mortgages carried a rate below the market rate, which averaged 6.41% that quarter (counted: Below 3%, 3% to 3.99%, 4% to 4.99%, 5% to 5.99%). Since Q4 2022 the market rate's quarterly average has been 6% or more, so the measure is the share below 6%.

## What it does not say

An estimate. The open top bucket is never split: with the market rate above 6% the loans between 6% and the market rate are not counted, so in those quarters it is a lower bound. With the market rate below 3% (most of 2020 and 2021) the only bucket below it is the open "below 3%" bucket, so no estimate is made for those quarters. Within a bucket, loans are not really spread evenly. NMDB is a nationally representative 5% sample of closed-end first-lien residential mortgages in Experian credit files, not a census; FHFA suppresses cells with fewer than three sample loans. Shares are by number of mortgages (VALUE1); by unpaid balance (VALUE2) the high-rate buckets weigh more because newer loans are larger. Rates are the contract rate: an adjustable-rate loan counts at its current rate.

## Source

Palanor calculation (src/lib/fhfa/nmdb.ts) from Federal Housing Finance Agency, National Mortgage Database (NMDB®) aggregate statistics, outstanding residential mortgage statistics, national, quarterly (https://www.fhfa.gov/document/d/nmdb/nmdb-outstanding-mortgage-statistics-national-census-areas-quarterly.zip); data dictionary and technical notes 2026Q1. NMDB is a joint FHFA and Consumer Financial Protection Bureau program; FHFA publishes these aggregates. U.S. government work: "information and materials produced by Federal agencies, including FHFA, are in the public domain" (fhfa.gov website policy). Read weekly by /api/cron/fhfa-state-hpi-sync. Market rate: Freddie Mac, Primary Mortgage Market Survey®, 30-year fixed, weekly, via FRED (MORTGAGE30US), averaged over each quarter with at least 10 weekly readings.