There are no rules or regulations stating that you cannot run your own DOT drug and alcohol testing program. However, there are so many regulatory requirements — such as a policy, a certified MRO, Reasonable-Suspicion training for supervisors, Post-Accident training, etc. — that it is often difficult for a small company to manage its own program. An effective C/TPA will also keep you informed of regulation changes and provide required reports.
Also, if the owner is also a driver, you are required to select a C/TPA in the FMCSA Clearinghouse.