APCM and ACOs: How It Fits the Shared Savings Program and REACH

If your practice or health center belongs to an ACO, the APCM conversation usually stalls on one question: does APCM help or hurt our shared savings? It is a fair question. APCM adds a monthly Medicare payment for many of your patients, and ACO results are measured against spending.

The honest answer is that APCM fits the Shared Savings Program more cleanly than most people expect, and the financial effect depends on things only your ACO can see. Here is what CMS has put in writing, what it means for assignment, spending and quality reporting, and the questions to bring to your ACO before you start.

APCM codes count as primary care services for assignment

The Shared Savings Program assigns beneficiaries to an ACO based on where they get their primary care. In the CY 2025 Physician Fee Schedule, CMS proposed adding APCM to the definition of primary care services used for assignment, and the federal regulation now reflects it. It lists APCM codes G0556, G0557 and G0558 as primary care services starting with the 2025 performance year, and for 2026 and later years (42 CFR 425.400(c)). For 2026 forward, the list also includes the behavioral health integration and collaborative care add-on codes billed with APCM.

In practical terms, APCM services count alongside office visits when CMS determines where a patient receives the plurality of their primary care. For health centers, note that CMS already treats services reported on FQHC and RHC claims as primary care services for assignment purposes.

ACO participation can satisfy APCM performance reporting

APCM requires the billing practice to be assessed on primary care quality, total cost of care and meaningful use of certified EHR technology. The CMS APCM services page lists participation in a Shared Savings Program ACO as one way to meet that requirement, along with the REACH ACO model and reporting the Value in Primary Care MIPS Value Pathway. For many ACO participants, this removes one of the harder APCM requirements.

CMS framed this as intentional. In its CY 2025 proposed rule fact sheet, CMS said APCM’s reduced administrative requirements for ACO participants were expected to help grow participation in the Shared Savings Program.

How APCM spending shows up in ACO results

APCM is paid under Part B. The Shared Savings Program calculates ACO expenditures from payment amounts on Parts A and B fee-for-service claims for assigned beneficiaries, according to CMS’s assignment and benchmark methodology specifications. So APCM payments for your assigned patients add to the ACO’s spending, the same way a CCM claim or an office visit does.

How that compares to your benchmark depends on your ACO’s agreement period, its benchmark methodology and how its region is trending. That is a calculation your ACO’s analytics team can run, and we would not try to answer it for you in a blog post.

So does APCM help or hurt shared savings?

It can go either way, and the honest answer depends on your patients and your ACO. A balanced view looks like this:

• The cost side. APCM adds a predictable monthly payment per enrolled patient to ACO spending, partly offset for patients who would otherwise have been billed for CCM, since a patient is on CCM or APCM in a month, never both.
• The utilization side. The services APCM pays for, such as care transitions after discharge, medication management and round-the-clock access, are the same activities ACOs invest in to reduce avoidable admissions and emergency visits. Whether that offsets the added cost depends on how well the program is run and which patients are enrolled.
• The revenue side. APCM payments go to the billing practice under fee-for-service, regardless of whether the ACO earns savings in a given year.
• The assignment side. Because APCM counts as primary care, it supports the care relationship that ties a patient to your practice for assignment.

Enrolling the patients who need the most coordination, such as dual eligibles and Qualified Medicare Beneficiaries billed under G0558, is where the care management work is most likely to matter. See APCM or CCM, which pays more for how the programs compare.

ACO REACH and capitation

CMS lists REACH ACO participation as a way to meet APCM’s performance reporting requirement. REACH works differently from the Shared Savings Program in one important way: REACH ACOs can take a risk-adjusted monthly capitation payment, either Primary Care Capitation or, in the Global track, Total Care Capitation. If your REACH ACO has elected capitation, ask it how APCM claims are treated under that arrangement before you enroll patients.

Timing matters too. CMS says REACH runs through performance year 2026, and its page refers to the LEAD Model beginning January 1, 2027. Ask your ACO how its plans for 2027 affect APCM.

Questions to bring to your ACO

• Does our ACO participation satisfy APCM’s performance measurement requirement for our practice?
• How would APCM spending for our assigned patients affect our expected results against benchmark?
• Are any of our patients in a capitated arrangement where APCM claims are handled differently?
• How does the ACO want APCM coordinated with its own care management programs?

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Frequently asked questions

Are APCM codes used in Shared Savings Program assignment?

Yes. G0556, G0557 and G0558 are listed as primary care services for assignment in the federal regulation, starting with performance year 2025.

Can ACO participants bill APCM?

Yes. APCM is billed under the Physician Fee Schedule, and participation in a Shared Savings Program ACO is one way to meet APCM’s performance reporting requirement.

Does APCM spending count against our ACO benchmark?

APCM payments for assigned beneficiaries are included in ACO expenditures, like other Part B claims. How that affects your results depends on your benchmark, so check with your ACO.

Does APCM help or hurt shared savings?

It depends on how much avoidable utilization the care management prevents relative to the added cost. Ask your ACO to model it for your panel before you scale.

At Droxi, we built Unlock to take on the operational side of APCM, so a practice can run the program without adding headcount. If you want to see what your Medicare panel could support, we are happy to run the numbers with you.