Rand Getlin of NFL Network first reported the news.
The deal is reportedly worth $3.8 million over three seasons, a salary bump from his $745,000 base salary from 2015.
Heyward-Bey grabbed 21 passes last season, putting up 314 yards and two touchdowns. His yardage total ranked sixth-best on the team, and fourth-best among Steelers receivers.
Heyward-Bey has struggled to produce in the NFL since being drafted with the No. 7 pick in the 2009 NFL Draft by the Oakland Raiders, averaging 26.2 yards in 104 career games.
The 29-year-old had his best season in 2011 while still on the Raiders, racking up 975 receiving yards and four touchdowns.