Prices for eggs, petrol and furniture dropped in the US last month, helping to slash inflation to less than half of its peak a year ago.
Inflation, the rate at which prices rise, was 4% over the 12 months to the end of May, the Labor Department said.
That was down from 4.9% in April and marked the 11th month in a row that price increases have eased.
The update comes as the US central bank meets to debate whether it needs to do more to fight inflation.
Officials have raised borrowing costs in the world's largest economy sharply since last year to try to rein in prices, pushing the Federal Reserve's key interest rate to more than 5%, from near zero in March 2022.
Analysts expect the Fed to leave interest rates unchanged this month, reflecting the progress made to ease price pressures as higher borrowing costs weigh on borrowing and spending.
The price of eggs has dropped 13.8% since last year - the biggest drop since 1951. Gasoline prices are down nearly 20%.
Overall, at 4%, inflation is the lowest it has been since March 2021, the Labor Department said.
But the update also showed that prices in many parts of the economy are still rising steadily - and far faster than the 2% rate the Fed considers healthy.
