Medicare Claims for Duplicate Laboratory Services Continue to Be Denied

The Centers for Medicare & Medicaid Services (CMS) says it will continue to deny claims for duplicate laboratory services unless the tests are deemed medically necessary, according to the Medicare Learning Network Connects newsletter from Oct. 1.

Based on the Medicare Claims Processing Manual, Medicare Administrative Contractors will deny duplicate tests that are not considered medically necessary. If a repeat test is medically necessary, those filing the claim must use CPT modifier 91 (repeat clinical diagnostic laboratory test).

The 2027 Medicare Physician Fee Schedule proposed rule includes a request for information on duplicate laboratory testing, imaging, and result sharing and interoperability. CMS said it is exploring options to address these issues in future rules.

Source:

https://www.cms.gov/training-education/medicare-learning-network/newsletter/mln-connects-newsletter-october-1-2026#_Toc241652759