One full query before a new driver starts
The Clearinghouse is a federal database of CDL driver drug and alcohol violations. Before a new driver performs a safety-sensitive function, including driving, you must run a full query. The driver must give electronic consent first, and your company must be registered. A full query releases the record to you. It shows verified positive drug tests, alcohol confirmations of 0.04 or higher, refusals to test, and violations reported by previous employers. A driver with any of these on record cannot drive until the return-to-duty process is complete.
A limited query every year, for every driver
At least once a year you must run a limited query on every driver in your testing pool. A limited query only tells you whether a record exists. It does not release the record. If it flags a driver, you have 24 hours to run a full query. Miss that window and the driver must stop all safety-sensitive work until the full query comes back clear. Keep each driver's consent on file, and keep every query record for three years.
Violations, return to duty, and your duty to report
The rules forbid driving with an alcohol concentration of 0.04 or higher, using alcohol within four hours of duty, and using controlled substances. Refusing a required test counts as a violation. After a violation, the driver must go through a substance abuse professional (SAP): evaluation, treatment, a negative return-to-duty test, and follow-up testing. You must report violations to the Clearinghouse within three business days of learning about them, and medical review officers report verified positives. Even when a third-party administrator files for you, you stay responsible for accurate reporting.
Compliance here is a trail of dated records. Your driver qualification files must agree with your query records. ELD mandate compliance is another dated requirement on the same fleet, and entry level driver training covers the drivers you hire next. When queries lapse, drivers sit and rigs stay parked. An operations audit will show which drivers have current limited queries on file and which are overdue.