Diagnostic radiopharmaceuticals or “tracers” allow scanners to visualize how organs function. In cardiac imaging, they reveal whether enough blood reaches the heart muscle. While the established approach, single-photon emission computed tomography (SPECT), remains widely available, Positron Emission Tomography (PET) offers clinical and workflow advantages that are supporting adoption in hospitals and independent cardiology practices. This creates opportunities across imaging providers, tracer manufacturers and radiopharmacy distribution. In this whitepaper, we dissect the distinctions in payment structure by isotope, namely Rubidium-82 and Flyrcado, across site of care. In addition, we highlight recent changes to Medicare policy toward hospital outpatient department reimbursement of isotopes. Finally, we provide context as to how the Medicare structure impacts commercial and Medicare Advantage treatment of these isotopes and modalities.