A Paradigm Shift in LDT Regulation

  • This page as PDF


The FDA’s final rule to regulate LDTs as medical devices brings on numerous uncertainties for stakeholders.

Finalization of Increased LDT Regulatory Oversight

On April 29, the Food and Drug Administration (FDA) released a final rule amending federal regulation to make explicit that in-vitro diagnostics (IVDs) marketed as lab developed tests (LDTs), are now considered medical devices under the Federal Food, Drug, and Cosmetic Act (FD&C Act). This change increases the FDA’s regulatory oversight of LDTs and phases out the use of general enforcement discretion with respect to a significant number of LDTs over a four-year period. Although several changes are consistent with the proposed rule released in September 2023, additional exceptions to the phaseout policy were established based on the nearly 7,000 comments received during the public comment period.

Phaseout Policy Requirements

The FDA finalized as proposed the five-stage phase out of enforcement discretion for LDTs. The FDA also released two draft guidance documents: the first one is related to the enforcement discretion policy during a public health emergency under section 564 of the FD&C Act, and the second provides considerations in the context of an immediate response to an emergent situation, absent a public health emergency declaration. Additional targeted guidance may be released throughout the phaseout period to assist manufacturers with compliance of FDA oversight of LDTs as IVDs.

Figure 1. Phaseout Policy Sequencing and Timeline

*Unless a submission is received prior to that date, in which case, enforcement discretion will still be used during the review.
**Most low-risk IVDs are exempt from premarket review.
QS: Quality System

The final rule also expanded upon the categories of LDTs exempt from the full regulatory requirements, which reflected changes from the exemptions originally outlined in the proposed rule. The final rule adds exemptions for:

  1. LDTs approved or under conditional approval by the New York State Department of Health Clinical Laboratory Evaluation Program (NYC CLEP)
  2. LDTs addressing an unmet need manufactured and used within a single integrated healthcare system

Figure 2. Test Categories Exempted from the Full Phaseout of General Enforcement Discretion

*As of 5/6/2024
DoD: Department of Defense; HLA: Human Leukocyte Antigen; RBC: Red Blood Cell; VHA: Veterans Health Affairs

Although enforcement discretion still applies to certain categories of tests, laboratories will still need to register as medical device manufacturers and comply with stage I and II requirements.

Rule Implementation Clarifications

The FDA held a webinar on May 14 to provide an overview of the final rule, explain the enforcement discretion phaseout policy, and answer pre-submitted questions from stakeholders. The FDA plans to host additional webinars related to the final rule and has already scheduled a call on June 5 to discuss both draft guidance documents.

During the May 14 webinar, the FDA largely reiterated which tests are subject to general enforcement discretion and the compliance timeframe for each set of requirements. The FDA clarified that:

  • If an IVD is manufactured and performed beyond a sole source laboratory (i.e., through a distributed model) it is not an LDT under the definition applied by the final rule, but FDA enforcement still applies.
  • LDTs marketed before May 6, 2024, that have not undergone any modifications to intended use, performance, or technology will still be subject to enforcement discretion but must comply with stages I and II of the final rule phaseout policy.
  • The FDA may determine when a test no longer addresses an unmet need due to increased availability of another FDA-authorized test, and it would then be subject to the full requirements of the phaseout policy.
  • If a lab runs a test that is similar to a test approved by the NYS CLEP enforcement but does not meet the standards of the test approved under NYS CLEP, the similar test will be subject to the phaseout policy.
  • The FDA intends to ensure sufficient resources are available for effective implementation of new requirements during user fee negotiations in 2027 and by enhancing its Third-Party Review Program.

Next Steps for Manufacturers of IVDs Marketed as LDTs

Manufacturers of LDTs on the market or in development should understand the regulations their tests are subject to under the final rule and the associated timeframe to become compliant, including any actions necessary for compliance regardless of continued general enforcement discretion. To support manufacturers with compliance, the FDA expressed its intention to issue additional guidance. During the webinar, the FDA also re-emphasized plans to pursue reclassification of Class III IVDs into Class I/II, which would result in fewer LDTs needing to seek approval through the premarket approval pathway.

The recent LDT rule follows a House Energy & Commerce Committee hearing on March 21, during which lawmakers discussed LDT regulatory reform. If a law were to pass that reforms diagnostics regulation, it would replace changes made by the final rule; however, the timeline for potential legislative action is not certain. Even without Congressional intervention, the rule is expected to face legal challenges from industry and other stakeholders.

Avalere experts in regulatory strategy, evidence, and market access can help you navigate these evolving dynamics for LDTs. If you have questions regarding how this rule will impact your organization and the diagnostics landscape, connect with us.

Webinar | A Closer Look at Patient Support Avalere experts explored how potential implications of the Inflation Reduction Act (IRA)’s out-of-pocket cap, in addition to other key regulatory and policy activities shaping benefit design and patient cost-share (e.g., EHB), could impact patient commercial and foundation assistance. Learn More
Watch Now
From beginning to end, our team synergy
produces measurable results. Let's work together.

Sign up to receive more insights about Regulatory Strategy and FDA Policy
Please enter your email address to be notified when new Regulatory Strategy and FDA Policy insights are published.

Back To Top