On September 21, 2026, CMS released the preliminary calendar year (CY) 2027 Clinical Laboratory Fee Schedule (CLFS) payment rates based on the second full private-payor data reporting cycle required under the Protecting Access to Medicare Act (PAMA). The preliminary median file is available here.
As expected, the results place significant downward pressure on laboratory reimbursement, with 1,171 of approximately 1,500 test codes showing lower weighted median rates than current CY 2026 payments. Some of the largest potential reductions are concentrated in the following services:
- Molecular pathology (-22%)
- Genomic sequencing (-23%)
- Microbiology (-19.3%)
- Immunology (-19.3%)
- Chemistry (-16%)
Payment reductions will be phased in between 2027 and 2029, with annual decreases capped at 15% per year.
The preliminary rates are based on private-payor rate and volume data reported to CMS during the 2026 reporting cycle. CMS has released supporting raw data for codes reported by at least 10 entities and is providing stakeholders with an opportunity to review and comment before final CY 2027 rates are published in November 2026. The public comment period will remain open for 30 days following publication. Comments must be submitted electronically to [email protected].
How Will the 2027 CLFS Rate Changes Affect Hospitals & Laboratories?
The proposed CLFS rates primarily affect laboratory tests that are separately paid under the CLFS, including hospital outreach and reference laboratory services. Many hospital outpatient laboratory tests furnished in conjunction with another payable Outpatient Prospective Payment System (OPPS) service are packaged into the payment for that service and are therefore not separately reimbursed at CLFS rates. This includes Q4-designated laboratory tests billed on the same claim as a separately payable OPPS service.
The financial impact of the proposed CLFS reductions will vary significantly across organizations. Independent laboratories and hospital outreach laboratory programs are likely to experience the greatest direct reimbursement pressure, while hospitals whose laboratory volume is predominantly associated with outpatient visits, surgery, emergency department services, or other packaged OPPS encounters may see a more limited direct revenue impact.
What Are the Next Steps for Providers of Lab Services?
Health systems, hospitals, and independent laboratories should immediately model the financial impact of the proposed rates across their laboratory service lines and assess implications for operating margins, outreach programs, and strategic investments. While this directly affects Medicare fee-for-service rates for services paid under CLFS, providers should also evaluate the impact on Medicare Advantage and commercial contracts if the negotiated rate is based on the CLFS.
Providers should also review the underlying CMS data collection and rate-setting methodology to verify that reported private-payor data was collected, aggregated, and analyzed accurately and that resulting payment rates appropriately reflect market conditions.
Given the magnitude of potential reimbursement reductions, laboratory providers should consider actively engaging with their state and national associations to identify data anomalies, develop coordinated feedback, and submit comments to CMS to help improve the accuracy and fairness of the final CY 2027 CLFS rates.
How Forvis Mazars Can Help
As federal healthcare policies continue to evolve, Forvis Mazars is committed to helping hospitals and health systems maintain regulatory excellence to support their pursuit of achieving health for their enterprises and those they serve. If you have questions about how the 2027 preliminary CY 2027 CLFS rates may affect your organization, please reach out to our professionals.