Accountable Care Organizations (ACOs) are collaborative networks of healthcare providers that come together voluntarily to deliver coordinated, high-quality care to defined patient populations—particularly those covered by Medicare. Their central aim is to improve health outcomes while reducing avoidable costs by shifting from traditional fee-for-service models to value-based care. ACOs span a range of payer arrangements, including the Medicare Shared Savings Program (MSSP), state Medicaid initiatives, commercial payers, and innovative models like ACO REACH. This diversity reflects the broader evolution of healthcare reform and the growing emphasis on accountability, integration, and performance.
This article explores key evidence-based strategies that have consistently driven success among high-performing ACOs. These include strengthening primary care, proactively managing high-risk patients, leveraging alternative care settings and supportive services, building robust data infrastructure and analytics, aligning incentives through multi-payer participation, fostering integration across specialty and post-acute care, investing in quality measurement and performance monitoring, and cultivating a culture of organizational learning and continuous improvement. Together, these strategies form a comprehensive framework for delivering better outcomes, improved patient experiences, and sustainable cost savings.
1. Strengthening Primary Care
Primary care is the foundation of effective ACO operations. Advanced primary care models leverage team-based care, with care coordinators managing high-risk patients and supporting care transitions. ACOs emphasizing primary care services, such as Annual Wellness Visits (AWVs) and chronic disease management, see improved patient outcomes and reductions in total cost of care (McWilliams et al., 2016). Preventive care strategies, such as AWVs, immunizations, and screenings contribute significantly to improved population health and reduced downstream costs.
Care coordination is essential in reducing fragmentation in clinical care. Studies show that ACOs with robust care coordination programs experience fewer emergency department visits and hospital readmissions, which is a key metric in quality reporting and performance year evaluations (McWilliams et al., 2016). Care coordinators play a pivotal role in managing care utilization, particularly among Medicare beneficiaries with multiple chronic conditions.
To address social determinant of health (SDOH) challenges such as lack of transportation, some ACOs have partnered with rideshare services or implemented mobile health units that bring preventive services directly to communities with limited access. Others have embedded social workers or community health workers within primary care teams to coordinate transportation, childcare, and other non-clinical supports, resulting in higher AWV completion rates and fewer missed appointments.
Engaging patients in their own care is a hallmark of high-performing ACOs. Patient engagement also influences quality reporting and measurement. Metrics related to medication adherence, follow-up care, and patient satisfaction feed into overall performance evaluations and determine shared savings eligibility.
Lower-performing ACOs often fail to fully implement care coordination infrastructure or lack sufficient care management staffing, leading to gaps in preventive care and avoidable acute care utilization. They also typically lack structured programs for preventive care and patient activation, contributing to higher acute care utilization and lower quality scores.
2. Managing High-Risk Patients
ACO savings often originate from a targeted focus on complex, high-cost patients—those who frequently use healthcare services due to multiple chronic conditions or serious illnesses. Successful ACOs rely on predictive risk stratification tools and detailed Medicare claims data to identify these individuals and anticipate their care needs.
Once identified, patients can be supported through the deployment of care managers, nurse navigators, or health coaches who provide ongoing guidance and coordination across care settings. These roles are essential for maintaining care continuity, reducing duplicative services, and aligning care with patient goals.
Research supports this approach, showing that ACOs with strong chronic disease outreach and integrated care planning not only reduce acute care utilization but also improve overall patient outcomes (Colla et al., 2016; Lewis et al., 2017).
3. Alternative Care Settings and Supportive Services
For patients with complex conditions or transportation barriers, home visits, remote patient monitoring (RPM), telehealth services, and palliative care programs are critical tools that help ensure care is accessible, timely, and compassionate. Delivering care in these alternative care settings effectively extends the reach of traditional primary care, enabling Accountable Care Organizations to better manage chronic conditions, reduce emergency department (ED) use, and prevent avoidable hospitalizations. The successful implementation of these services not only enhances care delivery but also enables ACOs to address social determinants of health, improve the patient experience, and support aging in place. By meeting patients where they are—both physically and clinically—ACOs can reduce care fragmentation and advance the goals of better care, better health, and lower cost.
Evidence supports the use of remote patient monitoring (RPM) in improving chronic disease management, particularly for conditions such as heart failure, diabetes, and COPD (Bashi et al., 2017; Greenwood et al., 2014; Janjua et al., 2021). Studies have shown that RPM can significantly reduce hospitalizations, length of stay, emergency department visits, and mortality for patients with heart failure, while also improving patient quality of life (Bashi et al., 2017). Additionally, ACOs implementing RPM alongside care coordination have reported improvements in patient satisfaction and medication adherence (Centers for Medicare and Medicaid Services, 2020). While outcomes for remote patient monitoring in COPD care are mixed, research more consistently shows that RPM can reduce hospital readmissions for patients with COPD (Janjua et al., 2021).
Another effective strategy is the use of community paramedics as primary care extenders. Community paramedicine programs deliver in-home care services such as medication reconciliation, chronic disease monitoring, and post-discharge follow-up, especially valuable for high-risk or homebound patients. Systematic reviews have found that community paramedicine programs have achieved significant reductions in emergency department (ED) visits, 911 calls, and hospital admissions, particularly among patients with chronic illnesses and those recently discharged from inpatient care (Chan et al., 2021). These programs have also demonstrated reductions in 30-day readmissions for patients with heart failure, chronic obstructive pulmonary disease (COPD), and multiple chronic conditions (Thurman et al., 2020).
Other innovative approaches to alternative care settings include deploying mobile clinics and installing telehealth kiosks in senior housing communities. These solutions play a critical role in closing care gaps, addressing access barriers, and supporting the delivery of high-value, patient-centered care aligned with the principles of accountable care.
4. Data Infrastructure and Analytics
Effective use of Medicare claims data—including data from Medicare Parts A and B, as well as Medicare Advantage plans—is a strategic asset in population health management. High-performing ACOs integrate clinical data, administrative claims, and social determinants of health (SDOH) to stratify risk, forecast costs, and guide targeted interventions. A strong data infrastructure is essential for sustainable success in accountable care, allowing organizations to shift from reactive care to proactive, data-driven management (Bodaken et al., 2016). High-performing ACOs leverage analytics to support care coordination, monitor outcomes, and drive performance improvement across the continuum of care. Advanced data tools are also used to benchmark provider performance, identify unwarranted practice variation, and enable real-time clinical intervention to prevent costly procedures or duplication of services. When evaluating provider performance, risk adjustment remains essential to ensure fair comparisons across different patient populations, accounting for differences in chronic disease burden, functional status, and socioeconomic risk factors.
According to Colla et al. (2016), ACOs that provide timely feedback to healthcare providers on cost and quality metrics outperform their peers. This includes sharing performance differences by provider group and utilizing dashboards that track quality measures and clinical outcomes.
In contrast, lower-performing ACOs may lack interoperable IT systems, resulting in delays in data access and limited capacity for proactive care management.
5. Multi-Payer Participation and Financial Alignment
While the Medicare Shared Savings Program has driven significant innovation, aligning incentives across all payers—including commercial insurers and Medicare Advantage—is vital for sustainable success. Participation in multi-payer ACOs allows for greater consistency in care coordination and quality improvement strategies across populations, greater return on investment in health IT and staffing, and alignment with value-based care incentives across the payer spectrum. Muhlestein et al. (2017) highlight that ACOs with broader payer participation showed more consistent cost savings and quality gains over time.
The shared savings payment model rewards organizations that reduce total cost of care while meeting quality benchmarks. Successful ACOs reinvest these savings into infrastructure, technology, and workforce development. However, financial incentives must be balanced with investments in patient care and primary care services.
High performing-ACOs are more likely to assume downside financial risk, which correlates with improved performance on quality metrics (Mechanic and Zinner 2016). Low performers often remain in upside-only tracks and underperform on value-based metrics.
6. Integration Across Specialty Care and Postacute Care
Collaboration with specialty care providers, skilled nursing facilities (SNFs), and home health agencies is crucial for care continuity. Studies show that ACOs with formal partnerships in postacute care settings can more effectively manage care transitions and reduce readmission rates. ACOs that actively manage postacute care pathways have achieved greater savings and quality improvements (Agarwal and Werner, 2018).
These integrations are especially relevant during care transitions following hospitalization, where uncoordinated discharge processes can lead to adverse clinical outcomes. Embedding care coordinators in hospitals and partnering with SNFs improves communication, medication reconciliation, and patient follow-up.
Low-performing ACOs often lack standardized protocols and visibility into postacute care outcomes, diminishing their ability to manage total cost of care.
7. Quality Measurement and Performance Monitoring
Quality metrics are central to ACO operations. Measures span clinical care activities, patient safety, preventive care, chronic disease management, and patient experience. CMS uses a composite score to assess ACO performance each performance year, which directly influences shared savings payouts.
Advanced ACOs employ real-time data dashboards, automated quality reporting tools, and predictive analytics to monitor performance. As quality measures evolve, so too must ACO strategies for quality improvement. Continuous training of care teams and feedback loops for primary care providers enable timely interventions and better alignment with value-based care goals.
Lower-performing ACOs may struggle with data integration and delayed reporting cycles, impeding their ability to make timely course corrections and meet quality targets.
8. Organizational Learning and Culture of Continuous Improvement
Successful ACOs adopt a mindset of continuous learning and improvement. According to Lewis et al. (2017), high-performing ACOs view care transformation as an iterative process rather than a fixed project. They pilot new initiatives, foster psychologically safe environments for staff to contribute ideas, and build cross-functional care teams. These care teams, including primary care providers, specialists, care coordinators, and administrative staff, collaborate on care transitions and clinical care activities, forming the backbone of quality improvement efforts.
Continuous quality improvement (CQI) can be embedded into daily operations through regular data review, performance feedback, and structured Plan-Do-Study-Act (PDSA) cycles. Leading ACOs invest in training staff on quality improvement methodologies, using clinical dashboards and scorecards to track progress toward key performance indicators. They create feedback loops that allow teams to adapt quickly to care delivery challenges and refine workflows based on measurable outcomes.
In contrast, low-performing ACOs often exhibit fragmented leadership, limited engagement of frontline staff, and resistance to organizational change. These characteristics inhibit agility and responsiveness to evolving patient care needs, and they often lack the infrastructure to support CQI processes, leading to stagnant performance and missed opportunities for improvement.
Challenges and Policy Considerations
Despite progress, challenges remain. Many ACOs struggle with financial risk exposure, limited interoperability, workforce shortages—particularly in rural areas—and a lack of analytics or data management expertise. Additionally, limited care management resources and insufficient tools to accurately identify the right patients for intervention hinder effective care delivery. Variations in patient population complexity and persistent fee-for-service models also contribute to disparities in performance.
Health policy must support ACO scalability through investment in health IT, flexible payment models, and standardized metrics. Policymakers can also incentivize integration with behavioral health and long-term care services, expanding the reach of ACOs across diverse care settings.
Unlocking Value-Based Success with Illustra Health
Illustra Health empowers ACOs to thrive by combining deep expertise in population health—rooted in Johns Hopkins’ legacy of clinical and analytic excellence—with hands-on partnership and innovative tools. Using advanced predictive analytics, Illustra’s patient segmentation methodology categorizes patients by morbidity burden and risk indicators, supporting the development of effective strategies tailored to specific population health needs.
Illustra Health removes the burden of data management by handling complex data integration and delivering clear guidance on actionable opportunities. This approach brings together disparate data sources—including medical claims, electronic health records, and social determinants of health—to create a unified, actionable view of population and patient-level opportunities.
Illustra’s population health experts work side-by-side with clients to interpret data insights and design strategies that drive meaningful outcomes, from increasing Annual Wellness Visit completion rates to reducing avoidable utilization. This comprehensive, data-driven support enables ACOs to be more agile, equitable, and effective in delivering value-based care.
Conclusion
Accountable Care Organizations represent a significant shift toward value-based care, aligning payment models with clinical outcomes, care coordination, and patient-centered strategies. Research shows that successful ACOs implement a range of evidence-based strategies including strengthening primary care, managing high-risk patients, utilizing alternative care settings and supportive services, building robust data infrastructure and analytics capabilities, participating in multi-payer programs with aligned financial incentives, integrating specialty care and postacute services, employing comprehensive quality measurement and performance monitoring, and fostering a culture of organizational learning and continuous improvement.
As ACOs continue to evolve within the Medicare Shared Savings Program and beyond, sustained focus on these interconnected strategies—along with ongoing quality improvement, risk adjustment, and preventive care—will be essential to delivering better patient outcomes and managing total cost of care.
References
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