Cassidy will earn around $3 million per season, according to TSN's Pierre LeBrun. Contract terms and salary are rarely revealed for coaches.
Cassidy has garnered an impressive .670 points percentage in two-and-a-half seasons behind the Bruins' bench, compiling a 117-52-22 record.
The 54-year-old replaced Claude Julien as the team's bench boss during the 2016-17 campaign. The club has made the playoffs every season with Cassidy at the helm, and Boston came within one win of capturing the Stanley Cup this past spring.