The nominal picture
The S&P Cotality Case-Shiller US National Home Price Index rose 1.1% year over year in May 2026, up from a 0.9% annual gain the prior month, according to the release published July 28. The 10-City Composite gained 2.4% and the 20-City Composite 1.6%. On a monthly basis the national index rose 0.6% before seasonal adjustment.
Metro-level dispersion was wide. Chicago led at 6.9% year over year. Las Vegas was weakest at -1.9%.
The real picture
The release noted that May marked the twelfth consecutive month of real, inflation-adjusted declines in home values, with CPI inflation at 4.2% for the reference month against nominal home-price growth of 1.1%.
Analysis: this is the distinction that most reporting on home prices omits. A homeowner whose property gained 1.1% in nominal terms over a year in which general prices rose 4.2% has lost roughly three percentage points of purchasing power on that asset. Nothing about the sale price has fallen, which is why the experience does not feel like a decline.
A full year of real declines is also a distinct market condition from a nominal correction. Prices have not crashed; they have stalled while the rest of the economy repriced. That mechanism erodes the real cost of housing gradually without forcing the kind of distress associated with falling nominal values — no widespread negative equity, no wave of underwater borrowers.
Methodology and timing caveats
Case-Shiller is a repeat-sales index using a three-month moving average, so the May reading incorporates transactions closed across March through May. The series is published with roughly a two-month lag and is routinely revised.
Because it pools transactions over three months and reports them months later, Case-Shiller is the slowest of the major price measures to register turning points. It is a confirmation tool, not an early warning.
The release covering July 2026 data was scheduled for September 29, after this article's publication date. The May release therefore remains the most recent verified reading in this series. FHFA's independently constructed index, covering the second quarter, showed a broadly consistent 2.1% annual nominal gain.
How this compares with the transaction data
Price indexes and sales volumes have been telling consistent stories through 2026, which strengthens confidence in both.
NAR reported the median existing-home price up 1.6% year over year in August, close to the low-single-digit nominal appreciation both major repeat-sales indexes recorded. That the median — a mix-sensitive measure — and the repeat-sales indexes agree suggests the mix of homes selling has not shifted dramatically.
Volume is where the strain shows. Existing-home sales ran at a 3.98 million annualized pace with 4.9 months of supply, the deepest in a decade, while prices still inched up. Markets usually resolve that tension eventually, either through prices adjusting or through volume recovering.
The real-terms decline provides a third path, and arguably the one currently in progress: nominal prices hold, inflation erodes them, and affordability improves gradually without any nominal correction. That adjustment is slow and largely invisible to sellers, which may be why it has not triggered the behavioural change a nominal decline would.