The Medicare Shared Savings Program sounds like something invented in a conference room with too many acronyms and not enough coffee. But behind the official name is a fairly practical idea: what if doctors, hospitals, clinics, and other health care providers worked together better, avoided wasteful care, improved quality, and shared in the savings when Medicare spent less than expected?
That, in plain English, is the heart of the Medicare Shared Savings Program, often called the MSSP. It is one of Medicare’s biggest value-based care programs and a major part of the national effort to move away from “more services means more payment” and toward “better care should be rewarded.” The program is built around Accountable Care Organizations, or ACOs, which are groups of health care providers that coordinate care for people with Traditional Medicare.
For patients, the program can feel almost invisible. You usually do not sign up for it the way you enroll in a Medicare Advantage plan. You do not lose your Medicare benefits. You do not need to memorize a provider network as if you are preparing for a game show. Instead, your doctor or health care organization may participate in an ACO, and Medicare may assign you to that ACO based on where you receive most of your primary care.
What Is the Medicare Shared Savings Program?
The Medicare Shared Savings Program is a voluntary program created by the Centers for Medicare & Medicaid Services. It allows groups of doctors, hospitals, and other health care professionals to form an Accountable Care Organization and take responsibility for the cost and quality of care delivered to a group of Medicare beneficiaries.
The program began operating in 2012 after being established under the Affordable Care Act. Its purpose is simple but ambitious: improve care coordination, reduce unnecessary spending, support preventive care, and keep quality standards high. In other words, it tries to reward health care teams for doing the thing everyone says they want: helping patients stay healthier without turning the medical system into a paperwork jungle.
How Accountable Care Organizations Work
An Accountable Care Organization is not an insurance plan. It is a coordinated group of providers. ACO participants may include primary care doctors, specialists, hospitals, rural health clinics, federally qualified health centers, skilled nursing facilities, and other Medicare-enrolled providers.
The ACO receives data from Medicare to better understand patient needs, identify gaps in care, and coordinate services. For example, an ACO might notice that a patient with diabetes has not had recommended lab work, or that a patient recently discharged from the hospital needs a follow-up appointment before a small problem becomes a large, expensive, siren-in-the-driveway problem.
The Big Idea: Better Care, Lower Costs
Medicare sets a financial benchmark for each ACO. This benchmark estimates what Medicare would expect to spend for the ACO’s assigned patients. If the ACO keeps spending below that benchmark while meeting quality requirements, it may earn a share of the savings. If the ACO is in a two-sided risk arrangement and spending goes above the benchmark, it may owe Medicare money back.
This is why the program is called “shared savings.” Medicare saves money, and the ACO can receive part of those savings as a performance payment. When designed well, everyone has an incentive to prevent avoidable hospitalizations, reduce duplicated testing, improve chronic disease management, and make sure patients are not bouncing around the health system like a pinball.
What Patients Should Know
If you have Traditional Medicare and your doctor participates in an ACO, your experience may not look dramatically different. That is actually part of the point. The program is designed to work in the background while encouraging your providers to communicate better.
You Keep Your Medicare Rights
Being assigned to an ACO does not mean you are locked into a network. You can still see any doctor, specialist, hospital, or provider that accepts Medicare. This is one major difference between an ACO in Traditional Medicare and many Medicare Advantage plans. An ACO may encourage you to use connected providers because it helps coordinate care, but it cannot block you from seeing another Medicare provider.
Your Data May Help Coordinate Care
Medicare may share certain claims information with the ACO so providers can coordinate your care more effectively. This can help doctors see the bigger picture, especially when a patient receives care from multiple specialists or facilities. Patients also have privacy rights and can contact Medicare if they do not want their claims data shared for care coordination.
You May Be Able to Choose Your Primary Clinician
Medicare beneficiaries can identify a primary care provider through their Medicare account. This can affect how Medicare connects a beneficiary with an ACO. Choosing a primary clinician helps signal which doctor or practice is most responsible for coordinating your everyday care.
Why the Medicare Shared Savings Program Matters
The Medicare Shared Savings Program matters because Medicare is enormous, health care spending is expensive, and poorly coordinated care can be frustrating for patients. When a program covers millions of people, even modest improvements in care coordination can have major effects.
In recent performance years, CMS has reported that ACOs in the Shared Savings Program generated substantial savings for Medicare while maintaining quality standards. For Performance Year 2024, CMS reported that participating ACOs produced billions in savings relative to benchmarks, with a large share of ACOs earning performance payments. That does not mean every ACO succeeds every year, but it does show why policymakers continue to treat the MSSP as a central value-based care model.
Key Facts About the Medicare Shared Savings Program
1. The Program Is Voluntary for Providers
Doctors and organizations choose whether to participate. They must meet CMS rules, form a legal ACO entity, report quality data, and accept accountability for assigned beneficiaries. This is not a casual “join by Friday and bring donuts” arrangement. ACO participation requires infrastructure, analytics, care management, compliance work, and leadership commitment.
2. It Applies to Traditional Medicare
The Shared Savings Program is connected to Original Medicare, also called Traditional Medicare. It is not the same as Medicare Advantage. This distinction is important because many patients hear “coordinated care” and assume it means a private plan network. In the MSSP, beneficiaries remain in Traditional Medicare and keep broad provider choice.
3. ACOs Must Meet Quality Standards
An ACO cannot simply cut spending and collect a reward. It must also meet quality requirements. These quality measures may include patient experience, preventive care, chronic disease management, hospital readmissions, and other indicators that show whether patients are getting appropriate care. In other words, an ACO cannot save money by ignoring people. Medicare is not handing out gold stars for medical hide-and-seek.
4. There Are Different Risk Levels
The program includes different tracks and risk options. Some ACOs begin with one-sided risk, meaning they can share in savings but are not responsible for losses. Over time, many move into two-sided risk, where they can earn higher rewards but may also owe money if spending exceeds targets. This structure encourages organizations to build confidence before stepping into deeper financial accountability.
5. Primary Care Is Central
Primary care is the engine room of the MSSP. A strong primary care team can identify problems early, manage chronic conditions, coordinate specialists, and prevent avoidable emergency department visits. Newer initiatives, such as the ACO Primary Care Flex Model, are designed to support stronger primary care financing inside the Shared Savings Program by giving participating ACOs more predictable resources for proactive care.
How Shared Savings Are Calculated
The basic calculation sounds simple: compare actual Medicare spending for assigned beneficiaries against a benchmark. If spending is lower and quality standards are met, the ACO may share in the savings. But, as with most Medicare policy, the simple version is the front porch; the full house has several hallways.
CMS benchmarks account for historical spending, patient risk, regional spending trends, and program rules. ACOs must clear a minimum savings rate before earning payments. This helps prevent random variation from being mistaken for true performance. For example, if an ACO saves a tiny amount that could have happened by chance, CMS may not count it as enough to trigger shared savings.
For ACOs in two-sided risk arrangements, the opposite can happen. If spending rises above the benchmark by enough to exceed a minimum loss rate, the ACO may owe shared losses. That financial pressure is intended to make accountability real, not decorative.
Examples of How the Program Can Improve Care
Example 1: The Avoidable Hospital Readmission
Imagine a Medicare patient named Robert who is discharged after treatment for heart failure. Without strong follow-up, he might miss medication instructions, gain fluid weight, become short of breath, and return to the hospital within two weeks. In an ACO, a care coordinator may call him after discharge, schedule a follow-up visit, review medications, and alert his primary care physician if symptoms worsen. The result may be better health for Robert and lower spending for Medicare.
Example 2: The Duplicated Test
Suppose Maria sees three specialists. Without coordination, two doctors might order the same imaging test because neither has access to the other’s records. An ACO can use data-sharing systems and care management workflows to reduce duplication. Maria avoids extra appointments, Medicare avoids unnecessary spending, and nobody has to ask, “Wait, didn’t we already do this?”
Example 3: Chronic Disease Management
A patient with diabetes, kidney disease, and high blood pressure needs regular monitoring. In a fragmented system, important care gaps can be missed. An ACO may use registries to identify patients overdue for screenings, lab tests, or medication reviews. Better routine care may reduce complications later.
Benefits of the Medicare Shared Savings Program
The main benefit is better coordination. When providers share responsibility for outcomes and spending, they have stronger reasons to communicate. Patients may receive more reminders, follow-up calls, preventive screenings, medication reviews, and help navigating the system.
Another benefit is the push toward value-based care. Traditional fee-for-service medicine pays for visits, tests, and procedures. That system can be useful, but it does not always reward prevention or coordination. The MSSP adds a layer of accountability that says, “Yes, services matter, but results matter too.”
The program also gives independent physician groups and community providers a way to participate in value-based payment without becoming part of a Medicare Advantage plan. This can be especially important for patients who prefer Traditional Medicare but still benefit from organized care management.
Challenges and Criticisms
The MSSP is not perfect. No health care payment model is perfect, and anyone claiming otherwise probably has a PowerPoint deck they would very much like you to admire.
One challenge is complexity. ACO rules, benchmarks, risk adjustment, quality reporting, patient attribution, and compliance requirements can be difficult. Smaller practices may need technology, staff, and capital to participate successfully.
Another challenge is uneven performance. Some ACOs generate strong savings; others produce little savings or even losses. Physician-led ACOs have often been associated with strong savings performance, while hospital-led organizations may face different incentives because hospitals earn revenue from admissions and procedures.
There are also concerns about whether benchmarks can accurately measure true savings. If benchmarks are too generous, Medicare may pay bonuses for savings that are not fully real. If benchmarks are too strict, good ACOs may leave the program because the financial risk feels unreasonable. CMS continues adjusting rules to balance participation, fairness, and fiscal responsibility.
Medicare Shared Savings Program vs. Medicare Advantage
The Medicare Shared Savings Program and Medicare Advantage are both connected to the broader movement toward coordinated care, but they are not the same thing.
Medicare Advantage plans are private insurance plans approved by Medicare. They often have provider networks, prior authorization rules, plan-specific benefits, and annual enrollment periods. The Shared Savings Program operates within Traditional Medicare. Patients keep Original Medicare coverage and can usually see any Medicare-accepting provider.
For beneficiaries, this difference matters. If your doctor is in an ACO, you are not automatically enrolled in a private Medicare plan. You still have your Medicare card, your normal Medicare rights, and your freedom to choose providers.
What Providers Need to Succeed in MSSP
Successful ACOs usually have several things in common. First, they invest in primary care. Second, they use data intelligently. Third, they identify high-risk patients early. Fourth, they build workflows for care coordination. Fifth, they focus on patient relationships instead of treating quality measures like a last-minute homework assignment.
Technology helps, but technology alone is not magic. A dashboard does not call a patient, explain a medication, arrange transportation, or notice that someone is confused after a hospital discharge. The best ACOs combine analytics with human follow-through.
Practical Patient Tips
If your provider participates in an ACO, ask how it affects your care. You might ask whether the practice offers care coordination, medication reviews, chronic care support, or help after hospitalization. You can also ask who to contact when you have questions between visits.
Patients should also keep a current medication list, choose a primary care provider, attend preventive visits, and tell each doctor about other specialists they see. Even in a coordinated system, patients and families remain important messengers. The health system is getting better at sharing information, but it still occasionally behaves like two departments separated by a moat.
The Future of the Medicare Shared Savings Program
The future of the MSSP will likely focus on stronger primary care, improved health equity, better data sharing, and more accountable payment structures. CMS has shown continued interest in expanding accountable care relationships to more Medicare beneficiaries, including people in underserved communities.
New payment options, such as prospective primary care payments in the ACO Primary Care Flex Model, show how Medicare is testing ways to give primary care teams more stable funding. Instead of paying only when someone comes in for a visit, these models aim to support proactive care: outreach, care planning, team-based support, and prevention.
For the program to keep improving, CMS must maintain a careful balance. Rules must be strong enough to protect Medicare dollars, but flexible enough to attract providers. Quality measures must matter, but not bury clinicians in reporting work. Savings must be real, but benchmarks must be fair. In health policy terms, this is called “alignment.” In normal human terms, it means everyone needs to stop pulling the wagon in different directions.
Experience-Based Insights: What the Medicare Shared Savings Program Feels Like in Real Life
From a patient’s point of view, the Medicare Shared Savings Program is often less dramatic than it sounds. There is usually no big enrollment moment, no shiny new card, and no welcome packet thick enough to stun a squirrel. Instead, the experience shows up in smaller ways: a call after a hospital stay, a reminder about a screening, a nurse checking on medication side effects, or a primary care office that seems unusually interested in preventing problems before they become expensive emergencies.
One common experience is improved follow-up. Many families know the uncomfortable feeling of leaving the hospital with a stack of papers, a new prescription list, and the vague sense that someone should be in charge but nobody is wearing the “I am in charge” hat. In an effective ACO, that gap is exactly what care coordination tries to close. A staff member may call within a few days, confirm that the patient understands discharge instructions, help schedule a follow-up visit, and flag warning signs for the doctor.
Another experience is more attention to chronic conditions. A patient with diabetes may receive reminders for A1C testing, kidney function monitoring, eye exams, or medication adjustments. A patient with high blood pressure may be encouraged to track readings at home. A patient with multiple prescriptions may receive a medication review to reduce confusion or unsafe combinations. These steps are not glamorous. They will not get their own medical drama on television. But they can prevent complications, and prevention is where shared savings often begin.
Families may also notice better communication between providers. For older adults seeing multiple specialists, coordination can be the difference between sensible care and medical ping-pong. An ACO does not automatically solve every communication problem, but it gives providers stronger incentives to share information, reduce duplicate tests, and understand the full patient picture.
For clinicians, the experience can be both rewarding and demanding. Many doctors appreciate the focus on prevention, team-based care, and outcomes. At the same time, ACO participation requires reporting, data review, care management systems, and financial discipline. A small practice may need help interpreting Medicare data, hiring care coordinators, or changing workflows. The program rewards smart organization, not just good intentions.
For health care administrators, the MSSP can feel like a long-term strategy rather than a quick win. Savings may take time. Building trust with physicians takes time. Cleaning up data takes time. Teaching teams to act on that data takes even more time. But when the model works, it can create a healthier rhythm: fewer avoidable hospitalizations, better preventive care, more informed patients, and a financial structure that rewards thoughtful care instead of endless volume.
The practical lesson is this: the Medicare Shared Savings Program is not about cutting corners. It is about cutting waste. The best version of the program does not ask doctors to do less for patients. It asks them to do the right things earlier, better, and with more coordination. That may sound modest, but in a system as large as Medicare, modest improvements can become very big results.
Conclusion
The Medicare Shared Savings Program is one of the most important value-based care programs in the United States. It encourages providers in Traditional Medicare to form Accountable Care Organizations, coordinate care, improve quality, and reduce unnecessary spending. Patients keep their Medicare rights and provider choice, while participating providers may earn shared savings when they meet financial and quality goals.
The program is not simple, and it is not flawless. Benchmarks, quality reporting, risk levels, and provider incentives all require careful management. Still, the MSSP represents a serious attempt to make Medicare smarter, not just bigger. When it works well, it supports better primary care, stronger follow-up, fewer duplicated services, and more attention to the patient’s full journey through the health system.
