Reviewed by certified coders + a maternal-fetal medicine physician / Updated for 2026
OB Coding Guide
26 · TC Modifier

Modifiers 26 and TC: The Professional/Technical Split

The short answer

Diagnostic services like OB ultrasound and NSTs split into two components: modifier 26 covers the professional work, the interpretation and written report, and TC covers the technical side, the equipment, sonographer, and overhead. Billing the code with no modifier claims the global service, both halves. The cardinal rule: across all billers, exactly one global claim, or one 26 plus one TC, never more.

Source: CPT 2026Source: CMS

The split

Most OB diagnostic codes are really two services wearing one code:

  • 26, professional component. The clinician’s interpretation and the written report. Follows the person who reads.
  • TC, technical component. The machine, the sonographer or nurse, supplies, and overhead. Follows whoever owns the equipment and employs the staff.
  • No modifier, global. Both components, billable only by a party that provided both.

This applies across the OB imaging bench, from the detailed anatomy scan 76811 down to limited scans, and to the NST 59025, where the tracing acquisition is technical and the reactivity interpretation is professional.

Who bills what

SetupImaging bill
Office owns the machine, own physician readsGlobal, no modifier
Scan done in hospital or facility-owned departmentPhysician bills 26; facility bills TC (or it rides the facility claim)
Clinic acquires images, outside specialist readsClinic bills TC, reader bills 26

The middle row is the one that catches OB practices with privileges: perform and read a scan at the hospital and the practice’s claim is 26 only, because the hospital owns the equipment and staff. Billing global from a facility place of service is the classic error here.

The overread arrangement

Common in maternal-fetal medicine: the OB office scans, an MFM specialist reviews the images remotely and issues the report. This is a component split across two organizations:

  • The office bills the code with TC for the acquisition
  • The MFM bills the same code, same date of service, with 26
  • The 26 claim requires a complete, signed written report; a verbal “looks fine” is not a billable interpretation
  • The arrangement should be documented up front: who bills which component, for which codes, at which sites

Done cleanly, the two claims are complements and both pay. Done loosely, they collide, which brings us to the traps.

Global billing traps

  • Two globals. Office bills unmodified, reader also bills unmodified. The second claim denies as a duplicate, and sorting out who refiles with which modifier takes longer than getting it right once.
  • Global plus a component. Office bills global, MFM bills 26. The payer sees the interpretation billed twice. The office claim needed TC.
  • Global in a facility POS. Unmodified code with a hospital place of service either denies or pays incorrectly, then claws back.
  • TC with no 26 anywhere. A technical claim with no interpretation on file invites a records request; every scan needs a report by someone.
  • Component modifiers on package codes. The OB global package codes and E/M visits have no PC/TC split; 26/TC belong only on codes with both components.

FAQ

What does modifier 26 mean in medical billing? It limits the claim to the professional component of a diagnostic service: the interpretation and the written report, without the equipment and staffing costs, which belong to the TC side.

Who bills the TC for an ultrasound? Whoever owns the equipment and employs the staff that acquired the images: the office for office-owned machines, the facility for hospital scans. Ownership of the machine, not presence in the room, decides it.

Can our OB office bill globally if an outside MFM reads the scan? No. If someone else furnishes the interpretation, the office provided only the technical component and bills TC; the reading physician bills 26. One party bills global only when it provided both halves.

Do modifiers 26 and TC change the payment amount? Yes, the fee schedule splits the global value between the components, with the technical share typically the larger piece on imaging. The two component payments sum to approximately the global rate.