Cohen’s opponent Linda Aguilar Hawkins received 47.24% of the vote, or 420 votes.
Neither Cohen nor Hawkins were able to surpass 50% of the votes for the seat during the March 1 primary race.
The commissioner precinct 2 seat covers Buda east of I-35 and portions of Kyle on either side of the corridor.
In November, Cohen will face off against the Republican nominee Mike Gonzalez who won against Andy Hentschke in March.
Results are unofficial until they are canvassed and certified.