From the
AMA 2021 outpatient guideline:
Test: Tests are imaging, laboratory, psychometric, or physiologic data. A clinical laboratory panel (eg, basic metabolic panel [80047]) is a single test. The differentiation between single or multiple unique tests is defined in accordance with the CPT code set. For the purposes of data reviewed and analyzed, pulse oximetry is not a test.
Unique: A unique test is defined by the CPT code set. When multiple results of the same unique test (eg, serial blood glucose values) are compared during an E/M service, count it as one unique test. Tests that have overlapping elements are not unique, even if they are identified with distinct CPT codes. For
example, a CBC with differential would incorporate the set of hemoglobin, CBC without differential, and platelet count. A unique source is defined as a physician or qualified heath care professional in a distinct group or different specialty or subspecialty, or a unique entity. Review of all materials from any unique source counts as one element toward MDM.
To me, multiple sites falls under "multiple results of the same unique test", therefore count it as one unique test. You would count each unique CPT code. If there is one code that incorporates all (or some) of the testing ordered, you count each unique CPT, even if that test contains several results. They give the specific example of BMP which includes glucose, calcium, potassium, BUN, creatinine, etc.
Hope that helps clarify it for you!