Medicare Payment for Clinical Laboratory Services 

Medicare consists of two parts: Medicare Part A covers inpatient hospitalization costs, once the annual deductible has been met, for almost everyone age 65 and older plus the permanently disabled and those with chronic renal disease. Coverage under Part A is automatic. Payment for inpatient care in most hospitals is based on a fixed fee determined for each diagnosis (diagnosis-related groups, DRGs).1 DRGs are not applied to physician services. Laboratory tests performed for Medicare inpatients are considered a part of the DRG payment. Medicare Part B covers physician services, outpatient clinical laboratory, and x-ray tests for eligible persons along with other medical services and supplies not covered under Part A. Part B is voluntary; however, most who are eligible sign up. There is an annual deductible and a 20% co-payment for all Part B services except outpatient clinical laboratory services.

Most clinical laboratory procedures are paid from laboratory fee schedules issued by individual Medicare carriers. Medicare carriers are contractors, usually large insurance companies, who administer Part B Medicare services in each state. There are 57 carriers, including one for each state and territory plus two in California and three in New York. All physician services, including pathology services not included in the laboratory fee schedule, are paid according to the Physician Fee Schedule. Unlike the laboratory fee schedule, under this schedule co-payments of 20% are collected from the beneficiary so that the actual payment received from Medicare for a given procedure is 80% of the Physician Fee Schedule amount.

Before Medicare pays for any test or diagnostic service, two basic criteria must be met: (a) the service must be covered by Medicare, and (b) the service must be medically necessary and indicated. Once these two criteria are met, Medicare pays for most clinical laboratory tests based on the applicable Laboratory Fee Schedule. Each carrier publishes a unique laboratory fee schedule and adjusts payment levels as determined by Congress during the annual budget process. Updates, when granted, are effective January 1st.

national fee limitations
National caps apply to most laboratory tests. These caps define the maximum amount a carrier may pay for a given test. The 1998 National Limitation amounts for any given test are based on 74% of the median amount listed on all carriers’ fee schedules for a particular laboratory test. National caps were reduced from 76% to 74% effective January 1, 1998, resulting in a reduction of 2.63% for most clinical laboratory tests.

Fee schedules may be adjusted only by statutory changes approved by Congress. When the fee schedule is adjusted by a given percentage, national caps are adjusted up or down by the same amount. Medicare payment for clinical laboratory tests is always the lowest of the fee schedule, the national cap, or the actual amount billed.