He will undergo a physical Thursday.
Howell, 30, made $2.85 million last season after signing a one-year deal with the Dodgers. He had a 2.03 ERA in 62 innings for the Dodgers. Howell had been seeking a three-year deal. If he reaches 120 appearances over the next two seasons, the $6.25 million option for 2016 becomes a player option, according to reports.
The agreement was earlier reported by MLB.com.
The Dodgers would like to add one more veteran reliever before spring training. They have had discussions with long reliever Jamey Wright.
Information from ESPN.com's Buster Olney was used in this report.