Healthcare pricing can be confusing, especially when navigating coverage for diagnostic services like a CT scan under Medicare. The ultimate cost to the patient is not based on the highly variable amount a provider initially bills, but rather on a specific figure set by the government. Understanding this figure, officially known as the “Medicare-Approved Amount,” is the reliable way to anticipate out-of-pocket expenses. This system creates a standardized payment baseline regardless of the medical facility.
Defining the Medicare-Approved Amount
The Medicare-Approved Amount (MAA) represents the maximum dollar figure that Medicare will recognize and pay for a covered health service, such as an outpatient CT scan under Medicare Part B. This value is often significantly less than the amount the facility initially charges. When a provider agrees to “accept assignment,” they commit to accepting the MAA as the full payment for the service and cannot legally bill the patient for the difference. The MAA serves as the benchmark against which all patient cost-sharing responsibilities are measured.
How Medicare Determines the MAA for Imaging Services
The determination of the MAA for outpatient diagnostic imaging is structured primarily through the Resource-Based Relative Value Scale (RBRVS), which assigns a value to each service. The RBRVS uses Relative Value Units (RVUs) to quantify the physician work, practice expense, and malpractice insurance associated with a specific procedure.
Each type of CT scan is identified by a unique Current Procedural Terminology (CPT) code, which corresponds to a set of RVUs. This system accounts for the differing complexity and time required for various imaging procedures.
The total RVUs are then adjusted to account for the geographic location where the service is provided, using a Geographic Practice Cost Index (GPCI). This adjustment recognizes that the cost of operating a medical practice varies across the country. The final MAA is calculated by multiplying the geographically adjusted RVUs by a national conversion factor, which translates the relative value into a dollar amount. The MAA can also differ based on the setting, meaning a CT scan performed in a hospital outpatient department will have a different MAA than one performed in a freestanding imaging center, reflecting facility costs.
Translating the MAA into Patient Cost Sharing
The Medicare-Approved Amount directly dictates the patient’s financial responsibility under Original Medicare Part B. For most covered outpatient services, the patient must first satisfy the annual Part B deductible before Medicare begins to pay. Once that deductible is met, Medicare pays 80% of the MAA for the CT scan.
The remaining 20% of the Medicare-Approved Amount is the patient’s coinsurance obligation. For example, if the MAA for a CT scan is $500, the patient is responsible for $100, assuming the deductible has been met. This coinsurance is a percentage of the approved rate, which protects the patient from excessive fees.
Patients often use supplemental coverage, such as a Medigap policy, to manage this 20% coinsurance portion. Medigap plans are designed to help cover the “gaps” in Original Medicare, including the deductible and coinsurance amounts. If a Medigap plan is in place, it may cover all or part of the 20% coinsurance, substantially reducing the patient’s out-of-pocket expense.
Practical Steps to Finding Specific CT Scan Costs
Because the MAA varies by specific procedure and geographic location, patients should use government resources to get a preliminary cost estimate. The official Medicare website offers a Procedure Price Lookup tool that allows users to search for national average costs for specific outpatient procedures. To get the most accurate estimate, it is helpful to have the specific CPT code for the CT scan ordered.
The most reliable step is to contact the medical facility’s billing department directly before the service is rendered. Patients should ask for the estimated cost for the specific CPT code and confirm that the provider accepts Medicare assignment. Confirming that the provider accepts assignment is important because it locks in the Medicare-Approved Amount as the maximum allowable charge.