Last medically reviewed: August 2026 Short answer: M54.5 (low back pain) was retired on October 1, 2021. It’s no longer a valid billing code. In 2026, use M54.50 (unspecified), M54.51 (vertebrogenic), or M54.59 (other low back pain) instead. Most pages still treat M54.5 as a working code. That’s wrong and it’s costing people claim denials. Let me explain what happened, what the code … Continue reading M54.5 Low Back Pain: The Retired Code + What to Use in 2026