Exploring New Models That Encourage Primary Care ACO Participation

Research has shown that accountable care organizations (ACOs) are most effective when they're led by primary care physicians. The challenge for the CMS Innovation Center is to boost primary care participation in the Medicare Shared Savings Program (MSSP) via models that can serve as on-ramps. A recent meeting hosted by the Primary Care Collaborative brought Innovation Center executives together with stakeholders to explore strategies to enhance ACO participation, including Advanced Primary Care Management (APCM), Primary Care Flex, and the upcoming LEAD model.

Here is a quick primer to help frame the discussion: 

• Advanced Primary Care Management (APCM) uses a monthly, bundled payment model to provide proactive services such as transitional care management and chronic care management through remote evaluations and virtual check-ins.
• The ACO Primary Care Flex model is designed to test how prospective payments and increased funding for primary care in ACOs affects health outcomes, quality, and costs of care within the MSSP.  The voluntary model started January 1, 2025, and runs through 2029.
• The Long-term Enhanced ACO Design (LEAD) model is a 10-year ACO model launching in 2027 as a successor to ACO REACH. Among the goals are increasing participation among independent, rural, and smaller practices while providing tailored care for high-need, dual-eligible, and homebound populations. During an initial planning phase from March 2026 through December 2027, CMS also will identify two states that are interested in partnering to develop a framework for ACO-Medicaid partnership arrangements.

Meredith Yinger, co-model lead of the LEAD Model at the CMS Innovation Center, noted that LEAD has a series of prospective payments that allow practices to invest in care management and care coordination functions that are otherwise challenging to sustain in a fee-for-service environment. “That can allow practices to identify and address chronic diseases earlier on and prevent disease progression, and that, in turn, enables the ACO to succeed from a total cost of care perspective,” she said. 

By taking on accountability for total cost of care in a model like LEAD, primary care practices have the opportunity to share in savings and they can use those savings to reinvest in core primary care functions, or even more enhanced functions — partnerships with community-based organizations or with specialists, Yinger added. “The stability and additional flexibilities that we allow these practices to use when they participate in an ACO model home in on that quarterback role that primary care physicians play. It super-charges it and allows those practices to succeed in an environment that's otherwise really challenging for primary care right right now from a sustainability perspective.”

Emily Bezold, a senior policy advisor at the CMS Innovation Center, highlighted specific policies within LEAD that are new or that build on aspects that were tested in prior ACO models that are intended to support the primary care community. One is lower beneficiary alignment minimums. One of the requirements for participation in ACO models is having a certain minimum number of Medicare fee-for-service beneficiaries, she explained. “We need this to be able to calculate a stable benchmark and stable quality measures, but it can be a real barrier to entry for smaller practices. That’s something that we've recognized, so in LEAD we'll be using lower beneficiary alignment minimums for programs that are new to ACO models and also organizations that focus on high-needs beneficiaries.” 

The next is related to something called voluntary alignment. There are two ways that patients get aligned to an ACO. The first is through looking at their claims history. The second is voluntary alignment, where a patient actually signs a form that says, "Yes, this is my primary care provider." You can use that for attribution in an accountable care model. Historically, there have been some restrictions around that process. In a couple of ways, LEAD aims to make that more flexible and responsive, allowing patients to do that more frequently and have that more frequently reflected in the ACO’s alignment.

The third thing Bezold highlighted involved new benefit enhancements. Another aspect of accountable care models involves waivers and flexibilities. “If an organization says I'm going to take accountability for cost and quality, we can waive some of the restrictions that we have in fee-for-service Medicare that are meant to control volume and over-utilization, because we trust that you're taking accountability,” she said. “One example is the medical nutrition therapy waiver, which allows access to sessions with a clinical nutritionist in traditional Medicare. Traditionally, who is eligible for that benefit is really limited, but in LEAD ACOs that take on global accountability can offer that benefit to a much larger range of patients with perhaps more mild hyperlipidemia and high blood pressure.”

Taking advantage of APCM in Colorado

Another speaker during the PCC webinar was Autumn Orser, M.D., M.B.A., chief medical officer for Carina Health Network, which empowers all of Colorado’s 19 community health centers (CHCs) with data, technology, and strategic support to advance value-based care and improve population health for underserved populations. Healthcare Innovation interviewed two Carina executives last November. In 2024 Carina’s member improved care for 11,829 Medicare beneficiaries across Colorado, while also generating $17.6 million in Medicare savings in the Medicare Shared Savings Program.

Orser said that the Carina team was really excited when APCM came out. “It’s a great opportunity to think about the patient as a whole, and not in that fee-for-service architecture that we were in with CCM [chronic care management],” she said. “The other thing that APCM did for us is expanded the population that was eligible for those services — not just a patient with two or more chronic conditions, but anybody who needed those services could receive them.”

She spoke about the importance of addressing the social complexity of their patients, about 50% of whom are dual eligible for both Medicaid and Medicare. “When I'm in the exam room with a patient, I can diagnose them and put them in a really great treatment plan, but unless I have some wraparound service providers who are going to make sure that they've got transportation to the pharmacy, a way to pay for their coinsurance when they get to the pharmacy, a system to be able to help them take their medication, especially if they're experiencing homelessness, it's really hard for us to have good outcomes for those patients," she said. "APCM is a solution for that.”

She mentioned that a lot of the rural health centers have trouble hiring people to do APCM for them. “It's hard to find medical assistants just to room patients and nurses to be able to take care of the things that they do. So how do we find a workforce to make sure that this is happening in all of our areas?”

Orser mentioned one solution Carina has found is to offer centralized service and to provide APCM at the ACO level. “That’s working relatively well. The only caveat there is what do we do with our Medicaid patients? How do we get them a similar service? That’s complex, because the states run Medicaid differently. How do we think about extending this to all patients, and not just those covered by Medicare and commercial?”

Orser also explained why Carina chose not to participate in PC Flex. “It was not an easy decision for us. We spent a lot of time analyzing what we were going to do, but ended up not moving forward with PC Flex. Part of that is that PC Flex was a really nice glide path to taking on risk. We’re already in the enhanced track of MSSP, with quite a bit of risk already. So it didn't feel like the right move at that time for us.

"The other thing that we were concerned about is that it was a CMMI initiative, and as we've experienced recently with Making Care Primary, those can go away depending on the administration's priorities,” Orser said. “So at a time when we were really looking for stability in an unstable landscape, it makes sense for us not to do it in order to reduce our operational uncertainty, but certainly we are excited to see the results of PC Flex as we move forward and and we are definitely looking forward to learning more about LEAD and what happens there, and which two states are going to be chosen for that.”

Aisha Pittman, M.P.H., senior vice president of government affairs at the National Association of ACOs, spoke about what NAACOS is hoping to learn from the Primary Care Flex model and how that might help shape the future of the MSSP.

“What I'm hoping to learn from it is how total cost of care and outcomes can improve with shifting the downstream payment mechanisms, focusing first on primary care. I think PC Flex reflects that. While we've had great innovations in the Innovation Center models with REACH and NextGen before that of having approaches for shifting to downstream payments, MSSP has not had that. This is the first step with PC Flex,” she said. “We know that when you combine this approach of total cost of care with enhancements to and shifting the payment flow for primary care, you see stronger cost performance and stronger quality outcomes for beneficiaries. I think the PC Flex model gives us the roadmap to fully test that within the model.”

Bezold added that the idea behind PC Flex is that historically in the MSSP you had to wait for the entire performance year to finish up and see shared savings that you'd then be able to reinvest in programs. “But that's up to a whole year that you're floating additional care, delivery, investments and activities without any sort of new payment, and that's really challenging, especially for smaller and independent practices." 

She said the the innovation in Flex of trying to provide an alternative payment and additional funds up front to provide stable monthly investment is “a core part of the hypothesis around how we actually help ACOs have the tools and make the investments to generate those shared savings on the back end.”