What Is CMS PAMA and How Does It Affect Lab Payments?

CMS PAMA lab reporting is the process under Section 216 of the Protecting Access to Medicare Act of 2014 that requires qualifying clinical laboratories to report their private payer rates to the Centers for Medicare & Medicaid Services, which uses that data to reset the Clinical Laboratory Fee Schedule. If your lab qualifies as an “applicable laboratory” based on its January–June 2025 revenues, your reporting window runs May 1, 2026 through July 31, 2026, and the rates CMS calculates from your submission take effect January 1, 2027.¹

Why PAMA Changed Lab Payment

Before PAMA, Medicare set Clinical Laboratory Fee Schedule (CLFS) rates using fee-schedule methodologies that often paid more than commercial insurers did for the same tests. Section 216 added Section 1834A to the Social Security Act and replaced that approach with a market-based system: Medicare’s payment for each test code is the weighted median of what private payers actually pay for it.² For most clinical diagnostic laboratory tests (CDLTs), the reporting cycle repeats every three years.³

Which Labs Have to Report

Not every lab that bills Medicare has to participate. CMS uses the term “applicable laboratory,” and a lab must meet all three of these tests to qualify:

It bills Medicare Part B under its own National Provider Identifier (NPI). Hospital outreach laboratories billing on Form CMS-1450 with type of bill 14x also qualify.
More than 50% of its total Medicare revenues during the data collection period come from the CLFS, the Physician Fee Schedule, or a combination of the two.⁴
It receives at least $12,500 in Medicare CLFS revenues during the six-month data collection period. Labs below this low-expenditure threshold are exempt, which spares most physician office laboratories from the reporting burden.⁵

Hospital Outreach Laboratories

Hospital outreach labs, which serve patients who are not admitted inpatients or registered outpatients of the hospital, occupy a special position. A hospital outreach lab that bills under the hospital’s NPI applies the applicable-laboratory tests using only the revenues tied to its 14x type of bill, not the hospital’s total Medicare revenue. If a hospital has multiple outreach labs under one NPI, CMS combines their 14x revenues for a single determination.⁵

What Counts as a Private Payer

The private payer definition is broader than many labs realize. It covers four categories:

Health insurance issuers as defined under the Public Health Service Act
Group health plans as defined under the Public Health Service Act
Medicare Advantage plans under Part C
Medicaid managed care organizations

Medicare Advantage and Medicaid managed care are the two most commonly overlooked, and both must be included.⁶ Traditional fee-for-service Medicare and traditional fee-for-service Medicaid are not private payers for reporting purposes.

The Current Reporting Timeline

Congress has repeatedly adjusted the PAMA schedule. The most recent change came on February 3, 2026, when Section 6226 of the Consolidated Appropriations Act of 2026 updated the requirements for CDLTs that are not advanced diagnostic tests.¹ The current cycle looks like this:

Data collection period: January 1, 2025 through June 30, 2025
Data reporting period: May 1, 2026 through July 31, 2026
New CLFS rates effective: January 1, 2027

The data collection window has already closed. If your lab qualifies, the numbers you will report are set; the work now is assembling and validating them for submission during the three-month reporting window. The next cycle after this one is expected to follow the standard three-year cadence, with collection in the first half of 2027 feeding rates that would apply for 2029 through 2031.⁷

How to Submit and What Data Goes In

Applicable laboratories submit through the CMS Fee-for-Service Data Collection System (FFSDCS), which is accessed via the CMS Enterprise Portal.⁸ Before you can submit, your lab must designate two roles, each registered through CMS Identity Management:

A Data Submitter, who uploads the files.
A Data Certifier, who formally attests that the submitted data is accurate and complete. The certifier’s attestation is what CMS relies on, and it carries real liability.

For each CDLT billed during the collection period, the submission reports the HCPCS code, the private payer rate, and the volume paid at that rate. The rate must reflect the final, fully adjudicated payment, including any patient cost-sharing such as deductibles or coinsurance — not the billed charge and not an interim amount. Each unique combination of payer and rate gets its own line, organized by HCPCS code.²

How CMS Turns the Data Into Rates

For each test code, CMS arranges the reported private payer rates by volume and finds the weighted median: the rate at which exactly half of the total reported test volume falls above and half falls below. That midpoint becomes the new Medicare CLFS payment for that HCPCS code.⁹ This is not a simple average. A single large lab reporting millions of tests at one rate can move the median more than dozens of small labs at a different rate. CMS excludes records where either the reported rate or the volume was zero.¹⁰

Penalties for Not Reporting or Misreporting

Labs that fail to report or that misrepresent their data face civil monetary penalties of up to $10,000 per day for each failure or misrepresentation. The statute is written broadly, so each unreported test can constitute a separate violation; a lab that ignores the obligation entirely could face penalties multiplied across every test it should have reported.¹¹ The $10,000 figure is also subject to inflation adjustment under the Federal Civil Penalties Inflation Adjustment Act.¹²

CMS has authority to audit submitted data and can require resubmission if it finds discrepancies. A lab that repeatedly fails to provide accurate data during an audit can receive an Invalid Data Submission finding, which triggers a follow-up validation audit where the lab must demonstrate compliance.

What Happens to Rates in 2027

Because the shift to market-based pricing produced significant cuts for many tests, Congress capped how far CLFS rates can fall in any single year, then repeatedly extended the freeze. For 2024 through 2026 there are no phase-in reductions at all.⁹ For 2027 through 2029, reductions resume with a 15% annual cap.¹ Many test codes are still being paid above their calculated weighted median, so once the cap kicks back in with the new rates on January 1, 2027, expect another round of cuts as payments move toward the market-based targets.

Advanced Diagnostic Laboratory Tests Follow Different Rules

Advanced diagnostic laboratory tests (ADLTs) are a distinct category under PAMA. They must be offered and furnished by a single laboratory, must have their own unique HCPCS code, and must be designated as ADLTs through an application to CMS.¹³ The key operational difference is timing: ADLTs require annual data reporting rather than every three years, so the dates above do not govern ADLT submissions.²

Pending Legislation

Two bills would rework parts of the current framework but neither has been enacted. SALSA (the Saving Access to Laboratory Services Act) would replace census-style collection with statistical sampling from independent, hospital, and physician office labs, extend the cycle to every four years, and exclude Medicaid managed care rates.¹⁴ The RESULTS Act, introduced in September 2025, proposes its own modifications and also remains in committee.¹⁵ Until either becomes law, the rules described here are the ones your lab has to plan against.

1
Centers for Medicare & Medicaid Services. CLFS and PAMA Reporting and Resources
2
GovInfo. Protecting Access to Medicare Act of 2014
3
Centers for Medicare & Medicaid Services. Medicare Clinical Diagnostic Laboratory Tests Payment System Final Rule
4
eCFR. 42 CFR Part 414 Subpart G – Payment for Clinical Diagnostic Laboratory Tests
5
Centers for Medicare & Medicaid Services. PAMA Reporting Frequently Asked Questions
6
eCFR. 42 CFR 414.502 – Definitions
7
Centers for Medicare & Medicaid Services. Summary of Private Payor Rate-Based Medicare Clinical Laboratory Fee Schedule
8
Centers for Medicare & Medicaid Services. PIA Information for Medicare Fee-for-Service Data Collection System
9
Centers for Medicare & Medicaid Services. Clinical Laboratory Fee Schedule
10
Centers for Medicare & Medicaid Services. Information Regarding the Final CY 2018 Private Payor Rate-Based Clinical Laboratory Fee Schedule Payment Rates
11
Social Security Administration. Social Security Act Section 1834A
12
Federal Register. Medicare Program – Medicare Clinical Diagnostic Laboratory Tests Payment System
13
Centers for Medicare & Medicaid Services. Guidance for Laboratories on ADLTs
14
U.S. Congress. S.1000 – Saving Access to Laboratory Services Act
15
U.S. Congress. S.2761 – RESULTS Act