Half of U.S. Mortgages Are Below 4%: Inside the Lock-In Effect

Nearly half of all outstanding U.S. home mortgages carried an interest rate below 4% at the end of June 2026, according to the Federal Housing Finance Agency's National Mortgage Database. On Oct. 22, 2026, Freddie Mac's weekly survey put the average 30-year fixed rate at 7.32%. That gap of three percentage points or more is the main reason so many homeowners who would otherwise move are staying where they are.

Economists call it the mortgage lock-in effect. Selling usually means paying off a cheap loan and taking out a new one at today's rates, and for many owners the jump in the monthly payment is too large to accept, even when the home no longer fits their needs.

How many owners are locked in

The FHFA National Mortgage Database is built from a nationally representative 5% sample of closed-end first-lien residential mortgages, and it puts the number of outstanding loans at about 51.4 million. Its second-quarter 2026 figures, the most recent published (covering loans outstanding as of June 30, 2026), break down this way:

Put another way, about two out of three mortgaged owners hold a rate below 5%, and about one in five holds a rate below 3%. The average rate across all outstanding mortgages was 4.4% in the second quarter of 2026.

The lock is loosening, slowly

The trend is moving in one direction, but not quickly. In the first quarter of 2022, just before rates began to climb, 24.6% of outstanding mortgages were below 3% and only 7.5% were at 6% or higher. By the second quarter of 2026, loans at 6% or higher (22.5%) outnumbered loans below 3% (19.2%). Every home sale, refinance and new purchase adds a higher-rate loan to the pool and retires an older one, but with sales activity low, that turnover takes years.

The database also shows owners staying put. The average outstanding loan was 80 months old in the second quarter of 2026, up from 59 months in the first quarter of 2022.

Why it matters for the whole market

A 2024 FHFA working paper, "The Lock-In Effect of Rising Mortgage Rates", measured the effect directly. The authors found that for every percentage point by which market rates exceed a borrower's original rate, the probability of selling falls by 18.1%. They estimated that lock-in prevented about 1.33 million home sales between the second quarter of 2022 and the fourth quarter of 2023.

The paper's price finding is the one that surprises many buyers. Higher rates on their own pushed home prices down by an estimated 3.3%, but the shortage of listings caused by lock-in pushed prices up by 5.7%. The net result: higher borrowing costs and higher prices at the same time, because the owners who might have sold simply did not list.

The paper also found that owners with less accumulated wealth have a harder time timing a sale around rates. Owners with substantial equity or savings have more ways around the problem, which is where the options below come in.

Options for owners who want to move anyway

Lock-in is a cost, not a wall. Owners who need to relocate, downsize or move closer to family have several paths, each with trade-offs that depend on equity, income and the type of loan.

1. Use the equity instead of a new loan

An owner with a low balance relative to the home's value can sometimes buy the next home with cash from the sale, or with a much smaller loan. A borrower who owes $120,000 on a home worth $450,000 is affected far less by a 7% rate on a small new mortgage than by a 7% rate on a full-size one. For owners moving to a less expensive area, the rate gap may matter much less than it first appears.

2. Sell to a buyer who can assume the loan

Most loans insured or guaranteed by the FHA, VA and USDA can be assumed by a qualified buyer with the lender's approval, which lets the buyer take over the seller's existing rate. That can make a home more attractive and support a stronger price. Most conventional loans contain a due-on-sale clause and cannot be assumed. Assumptions take longer than a standard closing, and the buyer usually has to pay the seller's equity in cash or with a second loan. Sellers with a VA loan should also confirm how an assumption affects their own VA entitlement. A deeper explanation is in this guide to assumable mortgages.

3. Watch for portable mortgages, but don't plan around them

A portable mortgage would let a borrower carry an existing rate to a new home. These loans are common in some other countries but are not a standard product in the U.S., where a mortgage is tied to a specific property. In November 2025, FHFA Director Bill Pulte said the agency was evaluating portable mortgages. On Aug. 3, 2026, Rep. Tom Kean Jr. of New Jersey introduced the MOVE Act (H.R. 10028), which would require Fannie Mae and Freddie Mac to begin purchasing and securitizing portable mortgages. As of late October 2026, the bill had been referred to the House Financial Services Committee with no further action. Owners should treat portability as a possibility, not an option they can count on today.

4. Bridge the gap between buying and selling

Owners who want to buy before they sell can use a bridge loan, a home equity line of credit or savings to fund the down payment on the next home. These tools can avoid a temporary move or a rushed sale, but they mean carrying two housing payments for a period. Bridge loans also tend to carry higher rates and fees than a standard mortgage. Owners should get the lender's terms in writing and set a realistic sale timeline before committing.

5. Keep the home as a rental

Some owners keep the low-rate home, rent it out and buy the next one with a new loan. The low payment can make the numbers work, but this turns a homeowner into a landlord, with tenant screening, repairs, insurance changes and vacancy risk. Lenders may also count only part of the expected rent as income, which affects how much the owner can borrow for the next home.

Taxes are the other big factor. Converting a primary residence to a rental can affect the federal exclusion on capital gains from a home sale, which generally requires the owner to have lived in the home for two of the five years before the sale. Owners weighing this route should read up on the home sale capital gains exclusion and talk with a tax professional before deciding.

6. Run the real numbers on the rate gap

A low rate saves money only on the balance still owed. An owner who is 10 or more years into a 30-year loan has paid down a meaningful amount of principal, and if part of the sale proceeds goes toward the next purchase, a smaller new loan at a higher rate may cost less per month than expected. Comparing the full monthly payment, including property taxes and insurance at the new home, often gives a clearer answer than comparing rates alone.

What would actually unlock the market

Rates would not need to return to 3% to change behavior. The FHFA research shows the effect scales with the size of the gap, so each step closer between market rates and existing rates frees up some owners. With the average outstanding rate at 4.4% and the 30-year market rate above 7% in October 2026, the gap remains wide. Until it narrows, most of the change will come from life events, such as retirement, job changes, growing families and estate sales, that force a move regardless of rates.

For owners and buyers following how these national patterns show up in local listings, current market coverage is available at Homes For Sale In Mesquite Nevada.