CLFS 2027: PAMA Rate Cuts Return After Six Years of Freezes
Short answer: PAMA-based rate cuts to the Medicare Clinical Laboratory Fee Schedule resume on January 1, 2027, after six consecutive years at a 0% reduction cap. CMS may cut any affected test by no more than 15% per year in 2027, 2028, and 2029. The new rates are being built from private payor data labs collected January 1 - June 30, 2025 and reported to CMS between May 1 and July 31, 2026.
For six years, the Clinical Laboratory Fee Schedule (CLFS) has been the rare corner of Medicare payment where nothing happened. Congress patched PAMA every year, the reduction cap stayed at 0.0%, and labs modeled flat CLFS revenue. That period ends in about four months.
Section 6226 of the Consolidated Appropriations Act, 2026 - enacted February 3, 2026 - was the last of those patches. It froze CLFS rates through December 31, 2026, but it also did something the earlier patches did not: it reset the data. Instead of pricing 2027 rates off stale 2019 private payor data, CMS will price them off a January 1 - June 30, 2025 collection window, reported during the May 1 - July 31, 2026 window that closed a month ago. According to the College of American Pathologists, that legislation delayed cuts of up to 15% on approximately 800 tests.
Those cuts are no longer delayed. This is what medical directors, lab CFOs, and revenue-cycle teams should be modeling now.
Six years of 0%, then a 15% cliff
CMS publishes the statutory phase-in schedule directly. The pattern is unambiguous: a 10% cap in 2020, then 0.0% every year from 2021 through 2026, then 15% per year for 2027 through 2029.
The 15% figure is a ceiling on the annual step, not a floor on the total. A test whose weighted median private payor rate lands far below its current CLFS rate does not fall all the way in year one - it falls 15%, then up to 15% again in 2028, then again in 2029.
How the cap compounds across three years
This is the part that gets missed in single-year budgets. A cap applied to the prior year's rate compounds. For a test priced at $100 on the 2026 CLFS whose new private payor benchmark sits well below that, the floor under three consecutive maximum reductions is not $55 - it is roughly $61.
Two practical consequences follow. First, a test at the cap in 2027 is very likely to be at the cap again in 2028 and 2029, so the 2027 CLFS release is effectively a three-year signal, not a one-year one. Second, tests near the cap deserve different treatment in a service-line margin review than tests that reprice modestly and then stabilize.
Where the 2027 numbers actually come from
Under PAMA, CMS pays for most clinical diagnostic laboratory tests based on the weighted median of private payor rates that applicable laboratories report. CMS defines a private payor as a health insurance issuer, a group health plan, a Medicare Advantage plan, or a Medicaid managed care organization.
The 2027 rates rest on data that is already locked. Labs collected private payor payment information for services furnished January 1 - June 30, 2025, and reported it to CMS between May 1 and July 31, 2026. That reporting window closed on July 31, 2026. There is no further opportunity to influence the underlying medians for this cycle.
What remains open is the process for new and substantially revised codes.
The CY2027 calendar that is still open
CMS has scheduled the CLFS Annual Public Meeting and the Medicare Advisory Panel on Clinical Diagnostic Laboratory Tests for September 15-16, 2026. That meeting covers payment determinations for new and substantially revised HCPCS codes under consideration for CY2027, plus public comment on reconsideration requests from the prior cycle.
Two payment bases come out of it:
- Crosswalking - the new test is judged comparable to an existing test, multiple existing codes, or part of a code, and payment is set from those.
- Gapfilling - no comparable test exists, so each MAC develops a local amount and CMS takes the median across MACs.
Gapfilling is slow by design. CMS notes it takes roughly nine months from the annual public meeting for MACs to establish and report their amounts, with MAC reporting due in April of the following year. A test gapfilled off the September 2026 meeting therefore has no established national amount until spring 2027 - a cash-flow gap that matters for any lab launching a novel assay.
The windows that close after November
CMS posts preliminary determinations each September and finalizes the basis and amount of payment each November through the annual instruction implementing the next year's CLFS. After that instruction issues, the public has 60 days to request reconsideration of either the basis of payment or, where crosswalking was used, the payment amount.
For gapfilled codes the sequence is different: once MACs report preliminary gapfilled amounts, CMS posts them and accepts public comment for 60 days; once final MAC-specific amounts are posted, reconsideration requests are accepted for 30 days, after which the amount is final and not subject to further reconsideration.
These are short, hard deadlines attached to a document most labs do not read until January.
What labs should do between now and January
- Rank revenue by CLFS-priced code. Identify which codes carry the top 80% of Medicare CLFS revenue and model each at a 15% reduction for 2027, then compounded through 2029. Flat-line CLFS assumptions in a 2027 budget are now indefensible.
- Separate CLFS exposure from PFS and OPPS exposure. Not every molecular service is paid off the CLFS. Mixing them produces a distorted forecast in either direction.
- Read the September preliminary determinations for your own codes. A crosswalk you disagree with is contestable; the reconsideration clock starts when the November instruction issues.
- Model gapfill timing, not just gapfill price. If a new assay is headed for gapfill, plan for a national amount arriving months after the code is live.
- Tighten the denial rate before the rate falls. When the payable amount per test drops, every avoidable denial costs proportionally more of the remaining margin. Our guide to why genetic testing claims get denied covers the failure modes worth eliminating first.
- Confirm coverage before volume assumptions. A repriced test still has to be covered to be paid. See our guides to Medicare coverage for genetic testing and the MolDX program's national footprint.
The strategic point is straightforward. Rate relief is no longer the variable a lab controls. Yield per accessioned sample is. Every claim that gets denied, appealed, or written off for a preventable coding or coverage reason takes a larger bite out of a smaller payment in 2027 than it did in 2026. That is the reconciliation ScreenMyGene automates - matching each order to a documented indication and the governing coverage policy before it becomes a claim.
Frequently asked questions
When do PAMA rate cuts to the CLFS resume?
January 1, 2027. CMS confirms there is no phase-in reduction in 2026, and that beginning January 1, 2027 through 2029, payment for an affected test may not be reduced by more than 15% per year compared with the prior year's amount.
How many tests are affected by the 2027 CLFS cuts?
The College of American Pathologists reports that Section 6226 of the Consolidated Appropriations Act, 2026 delayed cuts of up to 15% on approximately 800 tests through December 31, 2026. Those tests are the population now exposed beginning in 2027.
What data are the 2027 CLFS rates based on?
Private payor rates for services furnished January 1 - June 30, 2025, reported by applicable laboratories to CMS between May 1 and July 31, 2026. CMS sets payment from the weighted median of those reported rates. The reporting window is closed.
Can a lab still influence its 2027 CLFS rate?
Not the underlying medians - that data is submitted. Labs can still engage on new and substantially revised codes through the September 15-16, 2026 public meeting, the September preliminary determinations, and the reconsideration windows that open after the November final determinations.
What is the difference between crosswalking and gapfilling?
Crosswalking sets payment for a new test from an existing comparable test or codes. Gapfilling applies when no comparable test exists: each MAC develops a local amount, CMS takes the median across MACs, and the national amount typically arrives about nine months after the annual public meeting.
Educational disclaimer: This article summarizes Medicare payment policy as of August 2026 for general informational purposes. CLFS rates, statutory phase-in provisions, and determination timelines change with legislation and CMS rulemaking, and code-level amounts vary. This is not billing, legal, financial, or medical advice; verify against current CMS instructions and consult qualified reimbursement professionals. ScreenMyGene is clinical decision support and does not replace independent professional judgment.
Sources: CMS, Clinical Laboratory Fee Schedule (phase-in table and Section 6226 announcement, page last modified August 3, 2026); CMS, CLFS Annual Public Meetings (determination process, crosswalk/gapfill definitions, reconsideration windows); Federal Register notice 2026-08513, Meeting Announcement for the Public and the Medicare Advisory Panel on Clinical Diagnostic Laboratory Tests, September 15-16, 2026; College of American Pathologists, Protecting Access to Medicare Act (PAMA) for Laboratories.