WASHINGTON — Americans enjoyed a healthy increase in income last month but didn’t spend much of the gain.

The Commerce Department said Friday that personal income rose 0.4 percent in May, up from a 0.3 increase in April. But consumer spending rose just 0.1 percent last month after climbing 0.4 percent in both March and April.

After-tax income rose 0.6 percent, the biggest gain since December 2012. The gap between the May increase in income and the increase in spending drove the U.S. savings rate to 5.5 percent, the highest since last September.

Economists monitor consumer spending closely because it accounts for about 70 percent of U.S. economic activity. Despite the modest rise in May, analysts remain confident that consumers picked up their spending overall this quarter and will be eager to spend their savings and…