After a plea deal, prosecutors dropped the second charge of driving with an open container of alcohol. The Yankees pitcher, who played for the University of Nebraska before being a first-round Draft pick by New York in 2006, was pulled over on Oct. 18 by police in Lincoln, Neb.
"I am glad to put the legal aspect of this behind me," Chamberlain said in a statement released by the Yankees. "I made a mistake, and hope over time to turn this into a positive learning experience for me and others."
Chamberlain flew to Lincoln for his hearing after giving up two runs in 5 1/3 innings in the Yankees' 6-3 win over the Reds on Tuesday in Sarasota, Fla.
His court date had been rescheduled four times, most recently from Tuesday to Wednesday.
The 23-year-old right-hander went 4-3 with a 2.60 ERA in 42 games -- 12 starts -- during his second year in the Major Leagues in 2008.
Alden Gonzalez is an associate reporter for MLB.com. Bryan Hoch contributed to this report. This story was not subject to the approval of Major League Baseball or its clubs.