The Centers for Medicare & Medicaid Services has issued final Medicare payment rates for clinical diagnostic laboratory tests and advanced diagnostic laboratory tests in calendar year 2018. The rates are based on the weighted median of private insurer payment rates, as required by a 2016 final rule implementing changes to the Medicare clinical laboratory fee schedule under the Protecting Access to Medicare Act. In response to public comments, CMS made a number of changes to the final rates. These include changes to the national limitation amount for certain laboratory test codes; a payment floor for certain diagnostic and screening pap smears; and changes to the payment rate for home use hemoglobin A1c kits. CMS also deleted a procedure code that is not used on Medicare claims and corrected errors in the procedure codes for CYs 2019 and 2020. Twenty-three organizations, including the AHA, had urged CMS to suspend implementation of new payment rates, citing significant concerns with the data collection process used to establish the rates.