mediloop
Billing codes

CPT 73721

MRI of a joint in the leg, without contrast

An MRI of a lower-limb joint, most often the knee, without contrast. The usual scan for a suspected ligament or meniscus tear. Billed as a facility charge plus the radiologist's reading.

Billed to Medicare

$342

What providers submitted, on average, for this code in a hospital setting.

Medicare accepted

$63

What Medicare treated as payable. Not a commercial rate or a cash price.

The gap

5.5x

How many times the accepted amount the billed figure was.

National averages from the Centers for Medicare & Medicaid Services, 2024 data, retrieved 2026-09-14. Medicare fee-for-service, physician and practitioner claims only. The hospital's own charge for the same code is separate and is usually higher. Based on 215,822 services.

Among the 8 imaging codes on this site with CMS figures, this gap ranks 6 of 8 (median 5.5x). The widest is CT scan of the head, without contrast at 6x.

Watch out

Where this line goes wrong

Prior authorization

Almost always required by commercial insurers. A denial for missing authorization is usually the ordering provider's responsibility.

Both knees is two studies

Each joint is a separate code and charge. One knee billed twice is an error; two knees billed twice is not.

What to do

Check it, then ask

  1. 1

    Ask for the itemized bill and the imaging report, and check that each billed study has a report.

  2. 2

    Check the two halves match: the facility line and the radiologist's line should carry the same code for the same date.

  3. 3

    If the radiologist was out of network for an emergency visit or at an in-network facility, the No Surprises Act limits what you can be billed.

  4. 4

    If you are self-pay, ask for the hospital's published cash price for the scan; it is usually a fraction of the list price.

The full walkthrough for this kind of bill: Your bill came in above the estimate.

Think this line is wrong?

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Questions

People also ask

Is a knee MRI cheaper at an imaging center?

Almost always, and often by a large margin. For a planned scan, compare published prices before booking.

Sources

This page explains a billing code in general terms. It is not a coding, legal or medical opinion about your bill, and the code descriptions are mediloop's own plain-English summaries, not the official CPT descriptors, which are owned by the American Medical Association. Whether a charge was correct depends on the record of your visit and your payer's rules.