The contracts exempt from SCA coverage include: The SCA does not apply to certain types of contract services. through the use of “service employees.” The definition of “service employee” includes any employee engaged in performing services on a covered contract other than a bona fide executive, administrative, or professional employee who meets the exemption criteria set forth in 29 CFR Part 541. The McNamara-O’Hara Service Contract Act (SCA) covers contracts entered into by federal and District of Columbia agencies that have as their principal purpose furnishing services in the U.S. This fact sheet provides general information concerning the McNamara-O’Hara Service Contract Act.