What type of testing requires a provider to have a CLIA number?

A CLIA number is essential for any laboratory that performs testing on human specimens for the purpose of providing information for the diagnosis, prevention, or treatment of disease, or for determining the health status of individuals. The Clinical Laboratory Improvement Amendments (CLIA) regulate laboratory testing and require that all laboratories performing these tests be certified, regardless of the complexity level of the tests being performed.

Thus, having a CLIA number applies not only to complex testing but also encompasses moderate complexity and even waived tests, which are the simplest types of tests. This comprehensive requirement ensures that all laboratories adhere to standards that protect patient safety and test accuracy, regardless of the setting—whether outpatient, inpatient, or otherwise.

In summary, since all types of laboratory testing necessitate a CLIA number to ensure compliance with federal regulations, the answer is that it applies to all types of laboratory testing.