He was in private practice in Scranton, Pennsylvania, from 1951 to 1953, became an Assistant United States Attorney of the Middle District of Pennsylvania from 1953 to 1958, before returning to private practice from 1958 to 1969.
He became the president judge of the Court of Common Pleas of the 45th Judicial District of Pennsylvania from 1979 to 1986.
[1] Kosik was nominated by President Ronald Reagan on May 14, 1986, to a seat vacated by Judge Malcolm A. Muir on the United States District Court for the Middle District of Pennsylvania.
[1] He was best known for presiding over the "Kids for Cash scandal" corruption case, where he rejected the plea deals of two fellow judges and, after their convictions, imposing lengthy prison sentences on them.
Kosik moved to inactive senior status in February 2017 due to health issues at age 91, meaning that he would no longer hear cases or participate in the business of the court.