U.S. Housing Inventory History, 1999–2024

Housing inventory is the single most-watched supply-side metric in U.S. residential real estate, and the National Association of Realtors' "months of supply" series is the canonical way to track it. The number is straightforward: take the count of single-family existing homes listed for sale at the end of the month, divide by the seasonally-adjusted annual sales pace expressed monthly, and you get the number of months it would take to sell every home currently on the market at the prevailing pace. A small number means demand is overwhelming supply; a large number means supply is overwhelming demand.

The "balanced market" benchmark — and why we rarely see it

Real-estate professionals have long described 4–6 months of supply as a balanced market — neither side has structural pricing power, and home values track inflation roughly one-for-one. Below 4 months, sellers control the negotiation; bids over list price become routine, contingencies fall away, and price appreciation accelerates. Above 6 months, buyers control the negotiation; sellers cut prices, offer concessions, and wait longer between listing and contract. In the 26-year record visible in the table, the U.S. market has spent surprisingly little time in the 4–6 month range. The cleanest balanced years were the late 1990s and the post-recovery 2013–2015 window. Most other years have been notably tight (2017–2024) or notably loose (2007–2011).

The 2007–2011 inventory glut

The all-time peak in months of supply came in 2010 at 10.5 months — the depth of the post-subprime collapse, when foreclosure filings flooded the inventory pipeline at the same time that buyer demand evaporated under tight credit. From late 2007 through early 2012, the country sat in a structural buyers' market: builders had stopped starting new homes (see the housing starts series for the matching collapse on the supply side), but the sheer volume of distressed inventory took years to absorb. That period is the best modern example of how housing markets can be loose for sustained periods, not just brief recessions. The subprime explainer walks through the foreclosure-pipeline mechanics that generated this inventory.

The 2020–2022 inventory crash

The all-time low arrived in 2021 at 1.7 months — the tightest inventory reading on record. Three drivers compounded: pandemic-era shifts in housing preference (people wanted more space and rate cuts made it affordable), the Fed's emergency rate cuts in March 2020 pushed mortgage rates to roughly 2.7% by January 2021, and existing homeowners who had refinanced into low rates became reluctant to sell because doing so meant trading their locked-in rate for a much higher one. The result was a sellers' market more extreme than any earlier reading in the EHS series: bidding wars on properties that hadn't appraised, all-cash overbids on starter homes, and median time-on-market falling to under three weeks in many metros. The COVID housing surge longform covers the full mechanics of this period.

The rate-lock era — why supply is structurally low even now

Three years after rates spiked, U.S. months of supply remains well below the 4-month threshold that traditionally defines a balanced market. The underlying cause is not a builder problem — new construction has gradually recovered (see housing starts) — but a behavioral one: roughly two-thirds of outstanding U.S. mortgages carry an interest rate below 5%, locked in during 2020–2021, and homeowners with sub-5% rates are dramatically less likely to list. Selling means buying, and buying at today's 7%-area rates would more than double the typical homeowner's monthly payment for the same home. Until either rates fall meaningfully or enough time passes for the locked-in stock to age out, existing-home inventory will remain structurally lower than its pre-2020 norm. The rate-lock Q&A walks through the math of why this dynamic persists.

How months of supply differs from active listing count

One technical note worth flagging: months of supply is a ratio, not a count. A market can have rising listing counts and falling months of supply simultaneously if sales are rising even faster, and vice versa. The series above tracks the ratio. For an absolute count of homes listed for sale, sources like Realtor.com publish daily active-listing counts that diverge from NAR's series in important ways (Realtor.com captures all listed homes; NAR's denominator uses MLS-reported closings only). Both are useful; the months-of-supply ratio is the older and more economist-friendly metric because it normalizes for sales pace. For the broader sales pace itself, see U.S. existing home sales and the master data table.

Methodology note: figures are annual averages of monthly NAR EHS seasonally-unadjusted "months of supply" readings. Source: National Association of Realtors. Last data refresh: 2026-05-02 — verify against NAR's most recent year-end EHS release before citing any single observation in derivative work.

Annual months-of-supply table — 1999 to 2024

Months of supply = available existing-home inventory divided by current sales pace. The widely-used heuristic: under 4 months is a sellers' market, 4–6 is balanced, over 6 is a buyers' market. Annual figures are averages of monthly NAR EHS readings.

Related

• U.S. Existing Home Sales History
• U.S. Housing Starts History
• 30-Year Fixed Mortgage Rate History
• What is the rate-lock effect?
• What is the housing supply deficit?
• The COVID Housing Surge, 2020–2024
• The 2008 Subprime Housing Collapse