Overview
New regulations under the Clinical Laboratory Improvement Amendments (CLIA) introduced updated proficiency testing (PT) and PT referral rules that are now in effect. Although the regulations became effective on July 11, 2024, the final rule on PT Regulations Related to Analytes and Acceptable Performance (CMS-3355-F), issued by the Centers for Medicare & Medicaid Services (CMS), was not implemented until January 1, 2025.
PT and the rules around PT referral form a critical safety net for ensuring trust and accuracy in patient diagnostics. This is true not just for traditional labs, but also for a broad spectrum of healthcare providers, including hospitals, digital health companies, and telehealth providers offering at-home testing solutions. Behind the convenience and accessibility of modern clinical laboratory testing lies a complex web of rules governing quality assurance, namely PT, which evaluates a laboratory’s ability to deliver accurate and reliable results.
To assist providers in understanding the rule changes, CMS issued a guidance brochure for CMS-inspected laboratories, with the caveat that accredited laboratories must follow the applicable accreditation organization’s PT requirements.
In Depth
WHAT’S NEW IN THE FINAL RULE?
The updated regulations refine the PT framework, emphasizing stricter adherence and accountability for providers across the clinical laboratory spectrum:
- Clarified PT Requirements for Complex Testing. The new rule reinforces mandatory PT participation for all non-waived regulated analytes and specialties listed in Subpart I of the CLIA regulations. Providers performing moderate or complex tests must align with these standards.
- Stronger Focus on Waived and Unregulated Testing. While PT remains optional for waived tests – often used in point-of-care diagnostics (e.g., urine pregnancy tests) – the updated rule highlights the importance of voluntary participation to bolster quality assurance. For unregulated tests, which do not require PT, the updated rule highlights that entities holding a CLIA certificate must continue verifying the accuracy of these tests at least twice a year, with a renewed emphasis on documentation.
- Tightened PT Referral Provisions. New provisions aim to close loopholes in PT sample handling. Forwarding PT samples or discussing results with external entities is strictly prohibited, and enhanced enforcement measures are in place to deter violations. This prohibition applies to CLIA-certified laboratories that voluntarily participate in PT for waived tests as well as laboratories performing compulsory PT for non-waived tests.
- Enhanced Oversight and Reporting. Labs and providers must maintain robust records of their PT participation, results, and corrective actions. These records will be subject to stricter audits from CMS during biennial inspections to ensure compliance.
- Accountability for Cybersecurity. New provisions require labs to follow the manufacturer’s instructions for installing all software updates, including cybersecurity updates.
WHY DOES IT MATTER?
- Detecting Errors Early: PT acts as a safeguard, identifying potential issues before they compromise patient care.
- Ensuring Competency: PT validates the entire testing process, from staff proficiency to equipment accuracy.
- Building Confidence: Reliable results enhance trust among patients, providers, and regulatory bodies.
TO WHOM DOES THE PT FINAL RULE APPLY?
The PT final rule and guidance brochure apply only to CMS-inspected laboratories and therefore may not apply to accredited labs, which are subject to independent accreditation organizations’ PT requirements, or laboratories performing cytology testing, which have unique PT requirements set forth at 42 CFR § 493.945.
WHAT PT MUST A LABORATORY UNDERTAKE?
Labs performing non-waived tests must enroll in a US Department of Health and Human Services-approved PT program. The PT program will send the laboratory unknown test samples for each regulated analyte that the laboratory tests, usually three times a year. The lab then reports its results to the PT program, which evaluates the lab’s performance. A lab performing moderate and complex tests must enroll and participate in PT for each CLIA certificate it holds (i.e., one PT program per location), excluding certificates of waiver.
PT REFERRAL RISKS IN COLLABORATIVE HEALTHCARE MODELS
The interconnected nature of healthcare delivery – spanning hospitals, reference labs, and telehealth – increases the risk of forwarding PT samples to another lab or discussing results externally. This act, known as a PT referral, is a major violation under CLIA regulations, even if the referral is inadvertent. Potential consequences for PT referrals include:
- Revocation of the laboratory’s CLIA certificate.
- Restrictions on the organization’s ability to conduct testing (e.g., restricting lab director’s or owner’s lab operations).
- Reputational damage through public sanctions.
- Loss of patient trust.
STAYING COMPLIANT: WHAT LABS MUST DO
- Keep It In-House: Never send PT samples outside your lab, even if it is standard practice for patient specimens.
- Educate Your Team: Staff must clearly understand the difference between PT and patient sample handling.
- Take Immediate Action: If another lab sends you PT samples, report it to CMS or your state agency and refuse to test the samples.
RECOVERING FROM SETBACKS
Repeated PT failures or referral violations can lead to sanctions, including halted testing and suspended reimbursements. Labs can recover by:
- Diagnosing the Problem: Identify and address root causes of the breakdown and where it occurred, whether in lab analysis, sample logistics, or internal training.
- Earning Back Trust: Complete two consecutive successful PT events to regain compliance.
PT is not solely about avoiding penalties; it is about maintaining the highest standards of care. Every accurate test result reinforces patients’ trust in healthcare. By taking PT and referral rules seriously, labs can strengthen consumer confidence in their services, whether in-person or remote.
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