After law school, Groh worked at the law firm of Steptoe & Johnson from 1989 to 1991 and Mell, Brownell & Baker from 1991 to 1995. She took a position with the firm Semmes, Bowen & Semmes from 1995 to 1998. Groh became an Assistant Prosecuting Attorney for Berkeley County, West Virginia between the years of 1998 to 2002. From 2002 until 2006, she was an Assistant Prosecuting Attorney for Jefferson County, West Virginia. In 2006, she was appointed by (then) Governor Joe Manchin as a Judge of the 23rd Judicial Circuit Court of West Virginia. She was the first female Judge to serve in the 23rd Judicial Circuit and at the time of her appointment was only the third female circuit judge in West Virginia.[1][4] She served as a circuit court judge from her appointment in 2006 until March 19, 2012 when she resigned in order to receive her federal judicial commission. She is the first United States District Judge from the Eastern Panhandle of West Virginia.[5][3]