With the deal, Miley and Boston avoid arbitration. The agreement, according to USA Today's Bob Nightengale, includes a $500,000 signing bonus, $3.5 million in salary in 2015, $6 million in 2016 and $8.75 million in 2017.
The contract has a club option for 2018 worth $12 million as well as incentives worth $2 million and a $500,000 buyout clause.
Miley was the only remaining player in Boston who was eligible for arbitration.
Miley, 28, was picked in the supplemental first round of the 2008 draft by the Arizona Diamondbacks. In four years in Arizona, he was 38-35 in 106 games with a 3.79 ERA and 499 strike-outs.
The lefthander was acquired by the Red Sox from the Diamondbacks in a trade on Dec. 12. In his final year in Arizona he finished with a 4.34 ERA, 183 strikeouts and 75 walks over 201 innings in 33 starts. He finished the season with an 8-12 record.
Boston finished last season with a 71-91 record and in last place in the AL East.
- Christopher Woody