Top 25 clinical lab tests based on Medicare expenditures

On January 28, 2026, the U.S. Department of Health and Human Services Office of Inspector General (OIG) issued its review of Medicare Part B spending on laboratory testing for 2024. Required under the Protecting Access to Medicare Act of 2014 (PAMA), the annual report identifies the 25 clinical laboratory tests with the highest expenditures. Using Part B claims data for tests paid under the Clinical Laboratory Fee Schedule (CLFS), OIG’s analysis highlights notable shifts in utilization and spending. Among the most significant findings in 2024 was a marked increase in genetic testing.

Total Medicare Part B spending on lab tests

• In 2024, Medicare Part B spending on lab tests reached $8.4 billion, marking a 5% increase from 2023.
• Despite rising spending, the number of Part B enrollees receiving lab tests decreased by 15% from 2018 to 2024. This may reflect a broader shift from enrollment in Medicare Part B to enrollment in Medicare managed care (Part C).
• The increase in spending is not attributed to changes in fee schedule rates, which have remained the same since 2020.

Shift toward genetic testing

• Spending on genetic tests has surged, accounting for 43% ($3.6 billion) of total lab spending in 2024, up from 18% in 2018.
• Non-genetic tests, such as metabolic and lipid panels, have seen a decline in spending, totaling $4.8 billion in 2024.
• The rise in genetic test spending reflects a broader trend towards personalized medicine and advanced diagnostics.

Trends in lab test utilization

• The number of genetic tests paid under Part B increased by 160% from 2018 to 2024, while non-genetic tests decreased by 12%.
• The average payment per enrollee for genetic tests approached $800 in 2024, a 26% increase from 2023.
• Conversely, average per-enrollee costs for non-genetic tests remained stable, indicating a disparity in spending trends.

Laboratories receiving high payments

• In 2024, 346 laboratories received over $1 million each for genetic tests, with 55 labs exceeding $10 million.
• This trend indicates a concentration of high-value genetic testing services among a limited number of providers.
• The increase in high payments reflects the growing demand and reliance on genetic testing in clinical practice.

Analysis of top 25 lab tests

• The top 25 lab tests accounted for nearly half of all Medicare Part B lab spending in 2024, totaling over $4.1 billion.
• Among these, 10 tests were genetic, with expenditures reaching $1.5 billion, including tests for various cancers and infectious diseases.
• Spending for most genetic tests in the top 25 increased significantly, while spending for most non-genetic tests either declined or remained stable.

• The highest expenditure was for procedure code 87798, a genetic test for infectious agents, totaling $442.5 million, a 51% increase from 2023.
• The second highest expenditure was for procedure code 80053, the comprehensive metabolic panel, totaling $406.7 million, there was no change in test utilization from 2023 to 2024.
• The procedure code 81419, related to epilepsy, experienced a 392% increase in spending, highlighting the rapid growth in genetic testing for specific conditions.

Methodology and data sources

• The analysis utilized Medicare Part B claims data from 2018 to 2024, focusing on lab tests covered under the Clinical Laboratory Fee Schedule.
• Key metrics analyzed included total spending, number of tests, average payments per enrollee, and the number of laboratories and providers.
• The report emphasizes the importance of monitoring trends in lab test spending to ensure effective oversight and control of Medicare expenditures.