NEWARK — President Obama ordered federal agencies on Monday to stop asking most prospective employees about their criminal histories at the beginning of the application process, a change long sought by activists to help reintegrate former inmates into society.

During a trip to Newark, where he visited a residential drug treatment center, Mr. Obama said that America would be stronger if it found ways to move criminals emerging from prison into paying jobs, but that too many employers dismiss applicants out of hand if they are honest and check the box asking whether they have been convicted of a crime.

“It’s not too late,” Mr. Obama told an audience at the Newark campus of Rutgers University that included a few ex-offenders who had turned their lives around. “There are people who have gone through tough times, they’ve made mistakes, but with a little bit of help, they can get on the right path. And that’s what we have to invest in. That’s what we have to believe. That’s what we have to promote.”

Mr. Obama directed the federal Office of Personnel Management to delay inquiries into criminal history until later in the hiring process for most competitive federal jobs so applicants are not rejected before having a chance to make a positive impression. Most federal agencies have already taken this step, but officials said new rules would be published in the new year banning requests for criminal backgrounds until the most qualified applicants are sent to a hiring manager. Exceptions will be made for law enforcement, national security and other sensitive positions.