Bethancourt elected free agency Monday, Maddie Lee of the Chicago Sun-Times reports.
Bethancourt drove in seven runs in Wednesday's comeback win over the Pirates, going 3-for-5 with a home run, a double, a stolen base and three runs scored.
Bethancourt went 1-for-3 with a three-run home run in Friday's 6-3 win over the Cardinals.
The Cubs selected Bethancourt's contract from Triple-A Iowa on Friday, Taylor McGregor of Marquee Sports Network reports.
The Marlins released Bethancourt on June 27.
The Marlins outrighted Bethancourt to Triple-A Jacksonville on Wednesday.
Bethancourt went 2-for-4 with a home run and two RBI in Tuesday's extra-inning win over the Cardinals.
Bethancourt was reinstated from the bereavement list Tuesday.
The Marlins placed Bethancourt on the bereavement list Saturday.
Bethancourt is not in the starting lineup for Sunday's series finale against Arizona.