US inflation hits three-year high of 4.2% in May as Iran war drives energy costs

US consumer price inflation accelerated to a three-year high in May, the Bureau of Labor Statistics reported on June 10, as the energy shock stemming from the conflict with Iran pushed gasoline and other fuel costs sharply higher. The consumer price index rose 0.5% on the month and 4.2% from a year earlier, the fastest annual pace since April 2023 and an increase from 3.8% in April. It was the first time the headline rate had climbed above 4% in three years, and the third consecutive month of acceleration.

Energy was the dominant force behind the gain. Energy prices rose 3.9% in May alone and accounted for more than 60% of the monthly increase, with the annual energy figure surging 23.5%. Gasoline prices were up roughly 40.5% from a year earlier, while fuel oil posted an even steeper rise. Analysts and government data tied the spike to the disruption of shipping routes through the Middle East, including pressure on the Strait of Hormuz, which has rippled through global supply chains and lifted costs on everything from fuel to airfares.

Beneath the headline figure, underlying pressures looked more contained. Core inflation, which excludes volatile food and energy components, rose just 0.2% on the month, below the 0.3% economists had expected and slower than April's 0.4% pace. On an annual basis core prices were up 2.9%, the highest since September 2025 but still far below the headline rate, suggesting that much of the inflation impulse was concentrated in energy rather than spreading broadly across the economy. Core goods prices actually edged lower, while services categories such as shelter, transportation and medical care continued to firm.

Economists framed the report as painful but possibly near its peak. Mark Zandi, chief economist at Moody's, described inflation as "painfully high" while noting that the recent retreat in oil and gasoline prices suggested the headline rate may be cresting. Others echoed that view, cautioning that even if May marks the high-water mark, the path back toward the Federal Reserve's 2% target is likely to be slow and uneven given how much of the recent surge is bound up with an unresolved geopolitical situation.

For households, the squeeze has been concentrated in unavoidable essentials. Commentators pointed out that gasoline, food, electricity and medical care had all been running above 3%, hitting consumers where discretionary substitution is hardest. That dynamic has weighed on sentiment even as some big-ticket categories, including new and used vehicles, stayed comparatively subdued amid soft demand and affordability constraints.

The data carried significant implications for monetary policy. Inflation has roughly doubled from the 2.4% annual pace recorded in January, a shift that has upended the rate-cut narrative that prevailed earlier in the year. With prices accelerating and the labor market holding firm, some analysts began floating the possibility that the Fed's next move could be a hike rather than a cut, a striking reversal from the easing path markets had penciled in only months earlier.

Even so, policymakers were widely expected to hold borrowing costs steady at their meeting scheduled for June 17, opting to assess whether the energy-driven spike proves persistent before adjusting policy. The combination of elevated headline inflation and softer core readings left the central bank with a delicate judgment about how much of the price pressure is transitory and tied to the conflict, and how much risks becoming embedded in expectations.

Markets took the release largely in stride, in part because the annual figure matched forecasts and the softer monthly core reading offered some reassurance. The report nonetheless reinforced the degree to which the inflation outlook, and by extension the trajectory of the dollar and US rates, has become tethered to developments in the Middle East and the behavior of energy prices in the weeks ahead.