Section 493.5 - Categories of tests by complexity(a) Laboratory tests are categorized as one of the following: (2) Tests of moderate complexity, including the subcategory of PPM procedures.(3) Tests of high complexity.(b) A laboratory may perform only waived tests, only tests of moderate complexity, only PPM procedures, only tests of high complexity or any combination of these tests.(c) Each laboratory must be either CLIA-exempt or possess one of the following CLIA certificates, as defined in § 493.2 : (1) Certificate of registration or registration certificate.(2) Certificate of waiver.(3) Certificate for PPM procedures.(4) Certificate of compliance.(5) Certificate of accreditation.60 FR 20043, Apr. 24, 1995