How do risk-based contracts differ from ACO attribution practices?

• A. Risk-based contracts attribute patients to providers based on past utilization; ACOs use prospective attribution.
• B. Risk-based contracts attribute patients based on past utilization; ACOs use retrospective attribution.
• C. Both use prospective attribution.
• D. Both attribute based on random assignment.

Answer: (A)

The main idea is how patients are assigned to a provider or organization for accountability and payment. In risk-based contracts, attribution is tied to patients’ past utilization—claims and historical care determine which provider is responsible for that patient’s costs. In contrast, an ACO assigns patients prospectively at the start of the performance period, based on enrollment or pre-set attribution rules, so the ACO begins the period with a defined patient panel it is responsible for coordinating. This distinction matters for planning and risk sharing: retrospective attribution under risk-based contracts can shift responsibility after care has occurred, while prospective attribution in an ACO establishes a fixed scope of care coordination from the outset.