The Medicare PFS payment formula breaks into three parts: the work value of what the doctor does, the cost to run the practice, and a geographic adjustment for where you live.

Medicare does not pay doctors a flat fee for each visit or procedure. Instead, it uses a formula called the Resource-Based Relative Value Scale, or RBRVS. This formula tries to pay based on what the service actually costs to deliver — the doctor's time and skill, the office overhead, and the local cost of doing business in that area.

The formula produces a number called a Relative Value Unit, or RVU. Medicare then multiplies that RVU by a dollar amount set by Congress each year, called the conversion factor. The result is what Medicare pays.

Understanding this formula matters if you are trying to figure out why your doctor's bill looks the way it does, or why the same procedure might cost different amounts in different places.

Key Takeaways

  • The Medicare PFS formula has three components: work RVU (the doctor's time and skill), practice expense RVU (office costs), and malpractice RVU (insurance costs), each adjusted for your geographic location.
  • A conversion factor set by Congress each year turns the RVU total into a dollar amount — this factor changes annually and affects all Medicare payments nationwide.
  • The same procedure can have different payment amounts in different cities because the geographic adjustment factor varies by location.
  • Medicare updates the work RVU values periodically based on surveys of what doctors report about how long procedures take and how much skill they require.

The three components of the RVU

The first component is work RVU. This measures the doctor's time, mental effort, technical skill, and stress involved in the service. A complex surgery has a higher work RVU than a routine office visit. Medicare determines work RVU values by surveying physicians about how long procedures take and how difficult they are.

The second component is practice expense RVU. This covers the cost of running the office: staff salaries, rent, equipment, supplies, and utilities. A procedure that requires expensive equipment or more staff time has a higher practice expense RVU. Medicare divides this into direct costs (supplies used during the procedure) and indirect costs (rent, utilities, administrative staff).

The third component is malpractice RVU. This reflects the cost of malpractice insurance for that particular service. High-risk procedures like surgery have higher malpractice RVU values than low-risk services like an office visit.

Medicare adds these three numbers together to get the total RVU for a service.

How the geographic adjustment works

The same RVU does not produce the same payment everywhere. Medicare multiplies each of the three RVU components by a geographic practice cost index, or GPCI. This index reflects the actual cost of doing business in your area — staff wages are higher in New York City than in rural Kansas, and office rent varies the same way.

There are actually four different GPCIs: one for work, one for practice expense, one for malpractice, and one for the overall calculation. A doctor in an expensive urban area will have higher GPCIs than a doctor in a less expensive region. This means the same procedure generates a higher Medicare payment in high-cost areas.

The GPCI values are updated annually by Medicare based on actual cost data from each region.

The conversion factor and annual payment changes

Once Medicare has calculated the adjusted RVU (the total RVU multiplied by the geographic adjustments), it multiplies that number by the conversion factor. The conversion factor is a dollar amount set by Congress each year. For 2024, the conversion factor was approximately $33.06 per RVU, but this number changes annually.

Congress sets the conversion factor based on a formula that considers how much Medicare spending has grown and what Congress decides the program can afford. When Congress does not pass a new conversion factor, a default formula called the Sustainable Growth Rate (SGR) would normally cut payments automatically. However, Congress has repeatedly blocked these cuts by passing temporary fixes or permanent changes.

Because the conversion factor changes every year, the same procedure can have different payment amounts from year to year, even if nothing else changes.

Why this formula matters for your medical bills

When you receive a bill or explanation of benefits from Medicare, the payment amount reflects this formula. If you see that Medicare paid less than you expected, it is often because the RVU for that service is lower than you assumed, or because your geographic area has a lower GPCI.

If your doctor accepts Medicare assignment (meaning they agree to accept Medicare's payment as full payment), they cannot bill you for the difference between what they charge and what Medicare pays. However, if they do not accept assignment, they can bill you for the difference, up to a limit called the limiting charge. Understanding the formula helps explain why that limiting charge is what it is.

How Medicare updates RVU values

The RVU values themselves do not stay the same forever. Medicare updates work RVU values based on surveys of physicians about how long procedures take and how much skill they require. These surveys happen periodically, and the results can shift payment amounts significantly.

For example, if a survey shows that a particular procedure now takes longer than it did five years ago, the work RVU for that procedure may increase. Conversely, if a procedure becomes faster or simpler due to new technology, the RVU may decrease.

Practice expense RVU values are also updated periodically based on actual cost data from medical practices. Malpractice RVU values change based on actual malpractice insurance costs in each specialty.

The difference between Medicare PFS and other payment methods

Not all Medicare payments use the PFS formula. Medicare also pays hospitals using a different system called Diagnosis-Related Groups, or DRGs, which pays a flat amount per hospital stay based on the diagnosis, not on individual services. Medicare Advantage plans (private insurance plans that contract with Medicare) may use their own payment formulas entirely.

The PFS formula applies to services provided by doctors, therapists, and other practitioners in office settings or as outpatient services. Understanding which payment system applies to your care helps explain why different types of care have different payment structures.

Frequently Asked Questions

Why does the same procedure cost different amounts in different cities?

The geographic practice cost index (GPCI) adjusts for the actual cost of running a medical practice in each region. Staff wages, rent, and equipment costs are higher in expensive urban areas, so Medicare pays more for the same procedure there. This is by design — it reflects real differences in what it costs to deliver care.

Can my doctor charge me more than the Medicare PFS payment?

If your doctor accepts Medicare assignment, no — they must accept Medicare's payment as full payment. If they do not accept assignment, they can charge you up to the limiting charge, which is 115 percent of what Medicare pays. You should ask your doctor's office whether they accept assignment before your visit.

What happens if Congress does not set a new conversion factor?

A default formula called the Sustainable Growth Rate would normally cut Medicare payments automatically. However, Congress has repeatedly blocked these cuts by passing temporary fixes or permanent changes. If Congress does not act, payments would decrease, but this has not happened in recent years due to legislative action.

How often do RVU values change?

Work RVU values are updated based on physician surveys, which happen periodically but not every year. Practice expense and malpractice RVU values are updated more frequently based on actual cost data. The conversion factor changes every year. Check the Medicare Physician Fee Schedule on the Centers for Medicare and Medicaid Services website for the current year's values.

Does Medicare PFS explore to all medical services?

No. The PFS formula applies to office visits, outpatient procedures, and services by doctors and other practitioners. Hospital inpatient care uses a different system (DRGs). Medicare Advantage plans may use their own payment methods. Ask your provider which payment system applies to your specific care.