How Specialists Get Paid Inside an ACO

An accountable care organization is accountable for total cost of care. A large share of that cost is generated by specialists whose payment is untouched by the arrangement. Understanding that mismatch is the starting point for everything in this module.

Why the mismatch exists

The ACO course explained that attribution generally runs through primary care, because primary care is where longitudinal responsibility naturally sits. Shared savings therefore flow to the organization holding the attributed population, and specialists appear in the model mainly as a source of cost.

Meanwhile the specialist continues to bill fee-for-service. Every procedure, imaging study, and follow-up visit generates revenue for them and spending for the ACO. Nothing in the structure of an ACO changes this.

The Medicare course noted one partial exception: from CY2026 the physician fee schedule pays qualifying APM participants a higher conversion factor than everyone else, and the gap compounds annually. That is a real inducement for specialists to affiliate with an advanced APM, but it operates on affiliation rather than on any individual clinical decision.

The arrangements that do change behavior

Arrangement	How it works	Where it fits
Employment	The specialist is salaried, often with productivity and quality components	Integrated systems
Co-management agreement	Payment for defined service-line management responsibilities, not for volume	Hospital and specialist joint governance
Specialty subcapitation	A fixed payment per attributed member for a defined scope of specialty care	Advanced markets, delegated risk
Episode or bundle participation	The specialist shares in episode results directly	Procedural specialties
Gainsharing distribution	A share of ACO or episode savings tied to individual contribution	Any, with legal structuring

Each transfers some accountability to the specialist. None is easy, and the ordering roughly tracks difficulty: employment is the blunt instrument, subcapitation is the sophisticated one and requires the specialist group to have enough volume for the actuarial math to work, which the finance course covered as the credibility problem in small populations.

The referral relationship is the real lever

Before payment redesign, there is a simpler mechanism most ACOs underuse. An ACO chooses where to send its patients. A specialist who is efficient, communicates back to primary care, and does not generate unnecessary follow-up is worth more to the ACO than one who is not, and directing volume toward them requires no contract change at all.

This is the same insight the commercial course drew about network design: when you cannot change the price, change the volume. Inside an ACO it is even more available, because referral decisions are made by clinicians the ACO already works with.

Worth remembering: the specialist alignment problem is often described as a payment design challenge, and it is at least as much an information problem. Most ACOs cannot say which cardiologist in their market produces lower total cost for equivalent patients, because the analysis requires episode-level cost and quality attribution that the data course described and few organizations have built. Without it, referral steering is based on relationships and reputation, which are poor proxies. The organizations that solved specialist alignment generally built the measurement first and the payment arrangement second.

Key takeaways

• ACO attribution and savings flow through primary care while specialists remain on fee-for-service.
• Employment, co-management, subcapitation, episode participation, and gainsharing each transfer some accountability.
• Referral direction is the most available lever and requires no contract change.
• Steering only works if the ACO can measure specialist-level cost and quality, which most cannot.

Sources

• CMS, Shared Savings Program guidance and regulations (opens in a new tab)
• CMS, Calendar Year 2026 Medicare Physician Fee Schedule Final Rule (CMS-1832-F) (opens in a new tab)