On May 6, 2024, the Food and Drug Administration (FDA) issued a landmark Final Rule clarifying that in vitro diagnostics (IVDs) marketed as laboratory developed tests (LDTs) under the Clinical Laboratory Improvements Amendment (CLIA) are now explicitly designated medical devices with the accompanying regulatory requirements. Although the FDA did carve out certain exceptions subject to their enforcement discretion including, most notably, grandfathering exceptions for certain quality system and FDA submission requirements, this decision will still be costly and burdensome for the IVD space as a whole. However, for those LDT diamonds in the rough with superior clinical validation, this Final Rule could instead present a significant market access opportunity if developers are quick to adapt.