New FDA Regulations

New FDA Regulations on Laboratory-Developed Tests

In FDA, Preclinical, Regulatory by Valynda Machen

Laboratory-developed tests (LDTs) are in vitro diagnostic tests designed, manufactured and used in a single laboratory. This is in contrast to in vitro diagnostic tests, which are designed or manufactured, even partially, outside of the laboratory that ultimately offers and uses them. LDTs can be used to measure or detect single or multiple analytes such as sodium, glucose, cholesterol or proteins, as well as to detect more complex targets such as genetic variations.

Currently, the US Food and Drug Administration (FDA) has chosen to exercise “enforcement discretion” with respect to the regulation of LDTs. In other words, they have been allowed on the market without prior FDA clearance or approval. This is mainly due to the fact that these tests have been relatively simple with limited availability. The nature and scope of LDTs has changed over time, however, following advances in technology and changes in business models—making them increasingly complex and, at least in FDA’s view, potentially more risky. For example, a genetic test intended for the detection of cancer risk may greatly influence treatment decisions concerning when and how, and in whom, to initiate therapy. If this test is not properly validated and is prone to false positives, it may result in the unnecessary exposure of patients to costly and potentially harmful medications, devices, and/or surgery. If the test is prone to false negatives, it could result in treatment delay.

In response to these issues, FDA posted draft guidances for LDTs in September 2014 and opened the 120-day comment period on October 3:

The draft guidance for the Framework for Regulatory Oversight outlines FDA’s plan for risk-based oversight and has divided LDTs into 3 major categories: 1) LDTs allowed to continue under enforcement discretion, 2) LDTs subject to partial enforcement discretion/partial regulation, and 3) LDTs subject to full regulation.

  • Continued enforcement discretion
    • Applies to:
      • LDTs used solely for forensic (law enforcement) purposes
      • Certain LDTs for transplantation when used in CLIA-certified, high-complexity histocompatibility laboratories
    • Enforcement discretion for all applicable regulatory requirements
  • Partial enforcement discretion
    • Applies to:
      • Low-risk LDTs (Class I medical devices)
      • LDTs for rare diseases and “Traditional LDTs” (the type that existed when enforcement discretion was initially implemented)
      • LDTs for Unmet Needs (when no FDA-approved or cleared equivalent is available)
    • Enforcement discretion for applicable premarket review and quality system requirements
    • Enforcement of other applicable regulatory requirements, including registration, listing, and adverse event reporting
  • Full FDA Regulation
    • Applies to:
      • High-risk LDTs (Class III medical devices)
      • Moderate-risk LDTs (Class II medical devices)
    • Enforcement of applicable regulatory requirements, including:
      • Registration, listing, and adverse event reporting
        • Beginning 6 months after guidance finalization
      • Premarket review requirements
        • Highest-risk LDTs: beginning 12 months after guidance finalization
        • Remaining high-risk LDTs: phased-in over 4 years
        • Moderate-risk LDTs: beginning 5 years after guidance finalization and phased-in over 4 years
      • Quality System requirements

The draft guidance for FDA Notification and Medical Device Reporting describes when and how laboratories will have to notify FDA regarding their devices and what information should be provided with each notification.

If your laboratory currently manufactures and uses, or is planning to manufacture and use LDTs, you should familiarize yourself with the draft guidances in order to prepare for any necessary action once the guidances are finalized. It is important to determine the type of LDT you have in order to identify what steps you need to take and when.

Experts at NAMSA can assist you in this process is regards to:

  • Notification
  • Registration
  • Listing
  • Adverse event reporting
  • Premarket submissions
  • Quality systems

Next Steps

  • Subscribe to our blog to stay informed on industry news and insights.
  • Contact Valynda Machen for further information.
  • For information regarding NAMSA’s services, visit our Regulatory page.



US Centers for Medicare & Medicaid Services. Clinical Laboratory Improvement Amendments (CLIA). Available at:

US Food and Drug Administration. Draft Guidance for Industry, Food and Drug Administration Staff, and Clinical Laboratories: Framework for Regulatory Oversight of Laboratory Developed Tests (LDTs).  Available at:

US Food and Drug Administration. Draft Guidance for Industry, Food and Drug Administration Staff and Clinical Laboratories: FDA Notification and Medical Device Reporting for Laboratory Developed Tests (LDTs). Available at:

US Food and Drug Administration. Laboratory Developed Tests. Available at:


Valynda Machen (CQA, RAC-US) has over 20 years of medical device experience in the areas of In Vitro Diagnostic (IVD) manufacturing, new product development, quality assurance and regulatory affairs. She holds a B.S. in Bacteriology from Iowa State University and obtained certifications in quality auditing and regulatory affairs. Valynda is currently a Senior Medical Research Manager for NAMSA.