The cost of the stationary engineer exam varies based on the licensing laws in the professional's city or state. In Maryland, for example, the exam fee is $65, while professionals in the jurisdictions served by Continental Testing Services pay $70, as of March 2015. The fee applies to both initial exams and retakes.
Applicants pay the exam fee up front, after which they must take the exam within 2 weeks. If the applicant fails the exam, he or she can take it again after 100 days have passed, but must pay the same exam fee again. These fees pay the salary of the proctor, as well as other administrative costs.