Keeping current on changes to laboratory certifications for common lab tests can save your practice time—and money. Since the passage of the Clinical Laboratory Improvement Amendments (CLIA) in 1988, all health-assessment laboratory tests are ranked for complexity, and their complexity dictates which labs can process Centers for Medicare and Medicaid Services (CMS)–reimbursed tests. In accordance with CLIA, each laboratory facility must register with CMS to receive a CLIA certification. There are five certifications, each with differing degrees of complexity, listed from least to most complex: Certificate of Waiver, Certificate of Provider-Performed Microscopy Procedures, Certificate of Registration, Certificate of Compliance, and the Certificate of Accreditation.