IDTF Billing 2026

42 CFR 410.33: The Enrollment Performance Standards

To enroll, and to stay enrolled, an IDTF has to meet a specific list of standards under 42 CFR 410.33(g). The facility must operate in compliance with all applicable federal and state licensure and regulatory requirements for patient health and safety. It has to maintain a comprehensive liability insurance policy of at least $300,000 per location, covering the place of business and all of the IDTF's customers and employees. Equipment has to meet applicable FDA standards, be maintained per manufacturer instructions, and testing personnel have to meet the qualifications for the tests they perform.

Site visits are part of the deal. Medicare Administrative Contractors conduct unannounced site visits as part of initial enrollment and ongoing revalidation, checking that the facility actually operates at the enrolled location, with the equipment and staffing the enrollment application described. An IDTF that's enrolled but not physically operating as represented is a revocation risk independent of any claims issue.

The Anti-Markup Rule: What It Actually Caps

42 CFR 414.50 is the provision most IDTF billing errors trace back to. When a physician or supplier bills Medicare for the technical component or professional component of a diagnostic test that was ordered by the billing physician, supplier, or a party related to them, and the test was not performed in the office of the billing physician or by a physician who shares a practice with the billing entity, the anti-markup rule caps the payment. The billed amount is limited to the lowest of: the billing physician's or supplier's actual charge, the net charge the performing supplier billed to the billing physician, or the fee schedule amount that would apply if the performing IDTF billed Medicare directly for that component.

The "shares a practice" test is the detail that trips up billing teams. It's not enough that the performing physician has some affiliation with the billing group. The CY2008 Physician Fee Schedule final rule expanded the anti-markup provision specifically to reach situations where the technical component isn't performed in the billing physician's own office, closing a gap that previously let off-site arrangements avoid the cap.

MIPPA Accreditation: The Advanced Imaging Gate

For advanced diagnostic imaging specifically, MRI, CT, PET and nuclear medicine, there's a second gate beyond IDTF enrollment. Section 135(a) of the Medicare Improvements for Patients and Providers Act of 2008 requires suppliers of the technical component of these modalities to be accredited by a CMS-approved accrediting organization, codified at 42 CFR 414.68. The accrediting bodies CMS recognizes include the American College of Radiology, the Intersocietal Accreditation Commission, and The Joint Commission. An IDTF furnishing advanced imaging without current accreditation isn't eligible for Medicare payment on the technical component of those tests, independent of whether the enrollment itself is otherwise in good standing.

None of these requirements are new, which is exactly why they're an easy audit target: enforcement doesn't require CMS to update anything first. A facility operating the same way it did two years ago can fail a 2026 revalidation simply because nobody re-checked the accreditation expiration date or re-ran the anti-markup math after a referral pattern changed.

Frequently Asked Questions About IDTF Billing

What is an Independent Diagnostic Testing Facility?

An IDTF is a Medicare-enrolled entity, fixed-location, mobile, or an individual nonphysician practitioner, that is independent both of an attending or consulting physician's office and of a hospital, and that furnishes diagnostic tests. IDTFs enroll under 42 CFR 410.33 and must meet a specific set of performance standards to enroll and to maintain that enrollment, separate from the standards that apply to a physician office or hospital billing the same tests.

What is the anti-markup rule for diagnostic tests?

Under 42 CFR 414.50, when a physician or supplier bills for the technical or professional component of a diagnostic test that was ordered by that billing physician or a related party, and the test wasn't performed in the office of the billing physician or by a physician who shares a practice with the billing physician or supplier, the payment is capped at the lowest of the billing physician's charge, the performing supplier's net charge, or the fee schedule amount that would apply if the performing supplier billed Medicare directly. The rule exists to stop a billing entity from marking up a test it didn't actually perform.

Does an IDTF need imaging accreditation to bill Medicare?

Yes, for advanced diagnostic imaging. Section 135(a) of the Medicare Improvements for Patients and Providers Act of 2008 requires suppliers of the technical component of advanced diagnostic imaging services, including MRI, CT, PET and nuclear medicine, to be accredited by a CMS-approved accrediting body under 42 CFR 414.68. An IDTF furnishing these modalities without current accreditation from a body like the ACR, IAC or The Joint Commission is not eligible for Medicare payment on the technical component.

How much liability insurance does an IDTF need to enroll in Medicare?

Under 42 CFR 410.33(g), an IDTF must maintain a comprehensive liability insurance policy of at least $300,000 per location that covers both the place of business and all the IDTF's customers and employees. This is one of several enrollment performance standards an IDTF has to meet initially and continue to meet to stay enrolled.