U.S. households became less confident about the economy in May, continuing to ease from a 14-year high seen earlier this year.

The University of Michigan on Friday said its consumer sentiment index was 98.0 in May, down slightly from an initial 98.8 reading for the month. Economists surveyed by The Wall Street Journal had expected a final reading of 98.8 for May, unchanged from April. This follows a 14-year high reading of 101.4 seen in March.

“Consumers...