DER Overview: What Every Designated Employer Representative Needs to Know

The Designated Employer Representative (DER) is responsible for managing critical aspects of a DOT drug and alcohol testing program. This includes oversight of random testing, reasonable suspicion and post-accident decisions, coordination with Medical Review Officers (MROs), recordkeeping, and audit readiness.

This overview provides a practical, plain-language breakdown of DER responsibilities under 49 CFR Part 40, helping employers understand what is required, what decisions fall to the DER, and how to maintain compliance year-round.

Whether you are newly assigned to the DER role or need a refresher, this guide is designed to help you act confidently and avoid compliance gaps.