Mr. Bustos often wanders around Union Square, the Lower East Side and Midtown, where he has gotten to know some of the homeless by name. “See that guy over there,” he said, walking down the Bowery. “That’s Cowboy Ritchie,” whose wife, Mr. Bustos added, “wants him to shave his beard off because it looks too good and the other women flirt with him.”

Other times, Mr. Bustos meets his unsuspecting new clients through friends and paying clients, who tell him about people in their neighborhoods. He does up to 10 haircuts a day.

He started offering haircuts to the homeless two years ago. The idea, he says, is to simply give back. “Whether I’m giving one at work or on the street, I think we can all relate to the haircut and how it makes us feel,” Mr. Bustos said. “We all know what it feels like to get a good haircut.”

In some way, Mr. Bustos, who lives in Jersey City, has always been generous about hairstyling, which he taught himself at a young age. When he was 14, Mr. Bustos set up a chair in his parents’ garage in Nutley, N.J., and cut friends’ hair for free, so they could pocket the barbershop money they got from their parents.