CLFS History

The Protecting Medicare and American Farmers from Sequester Cuts Act (Section 610), passed on December 1, 2021, delayed the reporting requirement under Section 1834A of the Act and delayed the application of the 15% phase-in reduction.

Section 1834A of the Act, as established by Section 216(a) of the Protecting Access to Medicare Act (PAMA), required significant changes to how Medicare pays for clinical diagnostic laboratory tests (CDLTs) under the Medicare CLFS.

Through December 31, 2017, we paid for outpatient clinical laboratory services based on a fee schedule, per Section 1833(h) of the Social Security Act. Payment was the lesser of the amount billed, the local fee for geographic area, or a national limit.

We set the national limits at a percent of the median of all local fee schedule amounts for each laboratory test code. Each year, we updated the fees for inflation based on the percentage change in the Consumer Price Index. Copayments and deductibles didn’t apply. Congress could pass legislation to modify the fees.

As of January 1, 2018, we use a new private payor rate-based CLFS payment system. The payment amount for most tests equals the weighted median of private payor rates. We update the rates under the CLFS every 3 years.

We published the CLFS final rule in the Federal Register on June 23, 2016. The CLFS final rule implemented Section 1834A of PAMA, which required extensive revisions to the Medicare payment, coding, and coverage for CDLTs.

Under the CLFS final rule, reporting entities must report certain private payor rate information for their component applicable laboratories. The data collection period was January 1–June 30, 2019.

Section 1834A(e) also requires we assign a unique HCPCS code for each advanced diagnostic laboratory test (ADLT) and each FDA-approved or cleared laboratory test (that’s not an ADLT). To request a unique level II HCPCS code, complete this form (PDF) (PDF).

PAMA, passed in 2014, required significant changes to how Medicare pays for CDLTs under the CLFS.

• Social Security Act: 1833(h)(1)(A)
• Social Security Act: 1833(h)(5)(A)

• CMS-1646-N- Public Meeting on New and Reconsidered Clinical Diagnostic Laboratory Test Codes-CLFS for CY 2017 (7/18/2016)  
• CMS-1668-N-Public Meeting Regarding New and Reconsidered Clinical Diagnostic Laboratory Test Codes for the Clinical Laboratory Fee Schedule for CY 2018  
• CMS-1697-N- Public Meeting on New and Reconsidered Clinical Diagnostic Laboratory Test Codes-CLFS for CY 2019 (6/25/2018)
• CMS-1719–N -Public Meeting on June 24, 2019 Regarding New and Reconsidered Clinical Diagnostic Laboratory Test Codes for the CLFS for CY 2020
• CMS-1724-N- Public Meeting on New and Reconsidered Clinical Diagnostic Laboratory Test Codes-CLFS for CY 2021
• CMS-1741-N- Public Meeting on New and Reconsidered Clinical Diagnostic Laboratory Test Codes-CLFS for CY 2022

• MLN Matters: Medicare Part B Clinical Laboratory Fee Schedule: Revised Information for Laboratories on Collecting ad Reporting Data for the Private Payor Rate-Based Payment System
• Calendar Year (CY) 2018 Clinical Laboratory Fee Schedule (CLFS) Final Determinations (PDF) (PDF)
• CY 2018 Final Private Payor Rate-Based CLFS Payment Rates (ZIP) (ZIP)
• HCPCS Codes with Revised Final CY 2018 Private Payor Rate-Based CLFS Payment Rates and Clarifications Regarding the Weighted Median Calculations (PDF) (PDF)
• CY 2018 - Preliminary Private Payor Rate-Based CLFS Payment Rates and Analytics (ZIP) (ZIP)
• CY 2018 - Summary of Data Reporting for the CLFS Private Payor Rate-Based Payment System (PDF) (PDF)
• CY 2018 – Clinical Laboratory Fee Schedule Test Codes Preliminary Determinations – Crosswalking or Gapfilling (PDF)