Buffalo will carry a a $2 million salary cap charge in 2016 and 2017 because of the bonus proration from these two contract years.
There was some talk that the Bills could have released Harvin during the season, but they ultimately elected to hold onto him and have said that they would like to bring him back.
Harvin was placed on season-ending injured reserve a few months ago, due to knee and hip injuries.
Harvin, 27, signed a one-year, $6 million contract with the Bills back in March after the Jets cut him loose.
In 2015, Harvin has appeared in five games and caught 19 passes for 218 yards receiving to go along with five carries and 31 yards rushing (6.2 YPC) and one total touchdown.