What is patient attribution in ACOs and why does it matter?

• A. Attribution refers to how a patient chooses their primary care physician.
• B. Attribution determines which medicine is prescribed.
• C. Attribution assigns patients to providers for measurement of costs and quality; it determines which care and savings count toward a provider's performance.
• D. Attribution is a financial term unused in ACOs.

Answer: (C)

In ACOs, patient attribution is the process of linking each patient to a specific clinician or provider group so their care can be measured for costs and quality. This matters because the spending, health outcomes, and any shared-savings payments are counted based on the patients attributed to that provider. So, the care delivered to those attributed patients and the savings generated from their care are what determine a provider’s performance and financial rewards. Attribution methods can vary—patients might be assigned based on where they receive most of their primary care, claims data, or preset rules—and can be set before or after the year ends. This mechanism is essential for holding providers accountable for a defined patient population, rather than for all care indiscriminately. It isn’t about choosing a primary care physician or about which medicines are prescribed, but about linking patients to providers for performance measurement in the ACO.