In 1981, Phillips was convicted of drug trafficking. Subsequently, he and his daughter Mackenzie made the rounds in the media in an anti-drug campaign, helping to reduce his prison time to only a month in jail, of which he spent three weeks (one week off for good behavior) at Allenwood Prison Camp, in Allenwood, Pennsylvania. Upon his release, he re-formed the Mamas and the Papas with Mackenzie Phillips, Spanky McFarlane (of the group Spanky and Our Gang) and Denny Doherty. Throughout the rest of his life, Phillips toured with various incarnations of this group.