📅 Updated July 2026📌 Source: FMCSA, TDOSHS⏱ 5 min read
A common point of confusion: the DOT physical's urinalysis is not a drug test. Here's how drug and alcohol testing actually works for Tennessee CDL holders.
The urinalysis performed during a DOT physical checks kidney function and glucose levels, not for drugs. Drug and alcohol testing is a separate process governed by its own federal regulations, distinct from the medical certification exam.
The FMCSA Clearinghouse
The FMCSA Drug and Alcohol Clearinghouse is a national database tracking CDL holders' drug and alcohol program violations. Employers are required to query it before hiring a CDL driver and annually thereafter. This applies nationwide, with no state-by-state variation, including Tennessee.
The Return-to-Duty Process
A "prohibited" Clearinghouse status blocks all CDL processing until the federal return-to-duty process is completed. No state, including Tennessee through TDOSHS, can issue, renew, upgrade, or transfer a CDL for a driver reported as prohibited, regardless of any other factor, until that federal process is fully satisfied.
Study for Your Knowledge Tests
500 real practice questions across all 3 Tennessee CDL modules.