The estimated annual test volume requirement for a CLIA certificate application depends on the type of testing being performed and the size of the laboratory or healthcare facility. The CLIA regulations establish different volume thresholds for different types of tests and laboratories. For example, a laboratory performing high complexity tests must have a minimum annual volume of 250 tests in each of the preceding three years, while a laboratory performing moderate complexity tests may have a lower volume requirement. It is important to note that these are minimum requirements, and some states or accrediting agencies may have higher volume requirements. Applicants should review the CLIA regulations and guidance documents carefully to determine the specific volume requirement for their laboratory or healthcare facility.