Medicare Part B Lab Spending Hits $8.4 Billion as Genetic Testing Captures 43% of Dollars

Why It Matters

The shift concentrates Medicare dollars in molecular diagnostics, creating both revenue opportunities and heightened compliance risk for laboratories.

Key Takeaways

• Genetic tests capture 43% of Part B lab spend.
• Test volume rose 160% since 2018, reaching 18M.
• Top 25 codes represent over $4.1B, half spending.
• Per‑enrollee genetic test cost jumped 26% to $794.
• Regulatory scrutiny intensifies as molecular diagnostics grow.

Pulse Analysis

Medicare Part B laboratory expenditures crossed the $8.4 billion threshold in 2024, marking a 5 % year‑over‑year increase. While routine chemistry and hematology panels still dominate test volume, they now account for less than 60 % of total spending. The real engine of growth is molecular diagnostics: genetic assays, representing only five percent of all Part B tests, absorbed 43 % of the dollar value. This shift reflects broader clinical adoption of precision medicine, expanded carrier‑screening programs, and the rising prevalence of oncology‑focused liquid biopsies, all of which command premium reimbursement rates. For clinical laboratories, the concentration of revenue in high‑priced genetic codes reshapes business models. Over 300 labs earned more than $1 million from Medicare genetic testing in 2024, and a handful surpassed the $10 million mark, underscoring the profitability of a focused molecular portfolio. However, the same data reveal a 12 % decline in non‑genetic test volume and a 15 % drop in overall Part B enrollee utilization, driven partly by migration to Medicare Advantage plans. Labs must therefore balance the lure of high‑margin assays with diversification strategies and vigilant compliance programs to mitigate audit risk. The OIG’s findings also signal policy implications. With the Clinical Laboratory Fee Schedule frozen since 2020, spending growth is being driven by utilization patterns rather than price hikes, prompting lawmakers to scrutinize the cost‑effectiveness of widespread genetic testing. Payers may respond with tighter medical‑necessity criteria or bundled payment models, while innovators continue to push down sequencing costs and expand test menus. Stakeholders that can demonstrate clinical value, manage documentation rigorously, and adapt to evolving reimbursement frameworks will be best positioned to capture the expanding share of Medicare lab dollars.