President Obama on Thursday commuted the prison sentences of 58 inmates serving in federal prisons across the country who have been convicted of drug crimes, just over a month after commuting the sentences of 61 other inmates.

The inmates were convicted of drug-related crimes such as possessing and intending to distribute cocaine or methamphetamine. Eighteen of the people receiving commutations were sentenced to life in prison.

Their sentences are set to expire on Thursday or on September 2.

Get Breaking News Delivered to Your Inbox

This comes only about a month after the president commuted the sentences of 61 people who were convicted of similar crimes. Most of that group will be released from prison at the end of July.

Mr. Obama has commuted more prison sentences than the past six presidents combined. He has commuted the sentences of 306 people while George W. Bush commuted 11 and Clinton commuted 61. At the same time, Obama has only pardoned 70 people, the fewest of any president since President James A. Garfield in the early 1880s.