He was admitted to the Virginia bar in 1964, District of Columbia -1964; Supreme Court of the United States - 1967; the D.C. Circuit, 4th Circuit, and the Federal Circuit Courts of Appeal and the U.S. Claims Court.

Mr. Cohen started his own practice in 1970. The firm of Sheldon I. Cohen, has handled government and private employment discrimination and national security cases since then. His primary practice in the last 18 years has been employment law with major emphasis on national security law and government employment law, representing various individuals, unions and employers, and appearing before the MSPB, FLRA, EEOC, DoD Office of Hearings and Appeals, state courts, Federal District Courts, Federal Courts of Appeal and intelligence community agencies. He won the first handicap discrimination case against the Federal government (Sheposka v. United States, 563 F.2d 1113 (Ct.Cl. 1977)). He also won the first government contractor security case under APA and Due Process Clause (Kartseva v. Dept. of State, 37 F.3d 1524 (D.C. Cir. 1994)). He obtained a reversal of the Office of Personnel Managements denial of retirement annuities for senate employees. (Conner v. OPM, 104 F.3d 1344 (Fed. Cir. 1997)). Mr. Cohen has won numerous cases before the Defense Office of Hearings and Appeals. They can be found on DOHA’S web site by searching under his name.