Radiology Billing Guide 2026: PC/TC Split, Modifiers, and Interventional Coding

By RCMAXIS Coding Team  ·  June 2026  ·  12 min read

Radiology billing is complex because every imaging study has the potential to be billed in three different ways — globally, as a professional component only, or as a technical component only — depending on who owns the equipment and who performs the interpretation. Layer in contrast vs. non-contrast rules, interventional radiology procedural coding, and NCCI bundling restrictions, and you have one of the highest-complexity billing environments in all of medicine. This guide breaks down each component systematically.

1. The Professional/Technical Component Split

Every diagnostic imaging service consists of two distinct components:

• Technical Component (TC): The equipment, facility, staff, and supplies needed to perform the imaging study. Billed by hospitals and imaging centers that own the equipment.
• Professional Component (PC): The radiologist's interpretation, report, and supervision. Billed by the radiologist or radiology group.
• Global Billing (no modifier): When the same entity owns the equipment AND employs the interpreting radiologist — the full service is billed once with no modifier.

2. Contrast Coding Rules: With vs. Without vs. With and Without

For CT, MRI, and MRA studies, the presence or absence of contrast determines which CPT code to use. Billing the wrong code — especially billing "with contrast" when no contrast was administered — is one of the most audited errors in radiology.

Key rule: "With and without" (code ending in 3) requires documentation of both pre- and post-contrast image acquisition. If the radiologist's report describes only post-contrast images, the correct code is "with contrast" — not "with and without." Billing "with and without" when pre-contrast images were not obtained is upcoding.

Oral vs. IV Contrast

For CT of the abdomen and pelvis, oral contrast is commonly used but does NOT alone qualify a study as "with contrast." Only IV contrast (or intrathecal for spine studies) supports billing the "with contrast" code. A CT abdomen/pelvis with oral contrast only = bill as "without contrast."

3. CT and MRI Code Families

4. Interventional Radiology Billing

Interventional radiology (IR) procedures combine an imaging guidance code with a procedural code. Many IR procedures require reporting both the procedural work and the imaging supervision and interpretation (S&I) separately. Understanding which code pairs are bundled vs. separately reportable is essential.

Common IR Code Pairs

5. Ultrasound Billing: Complete vs. Limited Studies

Ultrasound codes have two levels: complete and limited. Billing a limited study when a complete study was performed (or vice versa) is a common audit finding.

• Complete study: All required anatomical elements evaluated and documented. For example, a complete abdominal ultrasound (76700) requires evaluation of the liver, gallbladder, CBD, pancreas, spleen, and both kidneys.
• Limited study (76705): Only one or a few specific organs evaluated — always requires documentation of the clinical reason for the limited scope.

If a complete study is attempted but visualization is limited by patient factors (obesity, bowel gas), document the limitation and what was successfully evaluated. This justifies the complete code even if not all elements were visualized.

6. NCCI Edits and Radiology Bundling

The National Correct Coding Initiative (NCCI) has numerous bundling edits specific to radiology. The most common violations:

• Billing CT and MRI of the same body part on the same date: Rarely appropriate; requires strong clinical documentation of why both were medically necessary simultaneously.
• Bilateral ultrasound codes: Some ultrasound codes are inherently bilateral (e.g., renal ultrasound 76770 includes both kidneys). Do not separately bill for each kidney.
• Nuclear medicine + CT: PET/CT (78816) is a single code — do not separately bill the CT component (74177) when performed as part of a PET/CT.