The punk rock pioneers chose freedom — and chaos — over major labels. Pulling the plug while things are still working is one final act of rebellion.

“It’s like going to your own wake.”

Mike Burkett, known exclusively in the punk rock world as Fat Mike, was talking about the farewell tour for his band, NOFX, during which the group is traveling to 40 cities, with 40 songs per concert, celebrating their 40 years as a band.

The tour started a year ago in Barcelona and will end where it all began for them, in Los Angeles, with three shows from Oct. 4-6. Fat Mike, 57, along with Eric Melvin, Aaron Abeyta and Erik Sandin are, collectively, experiencing the feels.

“This is it,” Fat Mike, the band’s singer, songwriter and bassist, said of the prospect of touring again after this. “We aren’t Kiss, or Black Sabbath, or Mötley Crüe. This is the end.”

“It’s kind of sad, saying goodbye,” said Mr. Abeyta, 58, the group’s guitarist and trumpet player, who goes by the nickname El Hefe. “We’re family. We’re basically brothers. We’ve lived on the road together, on a bus, sometimes in the same bed.”

“It’s weird, it’s uncertain, it’s scary,” said Mr. Sandin, 57, the group’s drummer who was nicknamed Smelly for the drug-fueled flatulence of his earlier days. (He’s been sober and clean for years.) “I feel like I’m losing a leg.”