Jarrod "Rizz" Simmons, 21, yesterday pleaded guilty to distribution of controlled substances within 1,000 feet of a public housing facility.
He is scheduled for sentencing on July 31, the US Attorney's office in Boston reports.
Simmons was one of nine people arrested in January in connection with gang-related drug and gun incidents in the sprawling Mildred Hailey Apartments between Centre and Heath streets.
Simmons admitted he sold crack to a "cooperating witness" working with the feds and Boston Police in 2016 - wearing a GPS ankle bracelet while awaiting trial on local gun and drug charges.
Simmons's older brother, Joe, was also arrested on the same charge in January.