Radiology CPT Codes
Radiology billing is built on one split: the technical component (the machine, the tech, the facility) and the professional component (the radiologist's read). Almost every imaging code divides into TC and 26, and who bills what depends entirely on who owns the equipment and who interprets. After that, it's about picking the right code from families that differ only by contrast use and body area.
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Radiology CPT codes
Chest X-ray, 2 Views
The standard PA and lateral chest radiograph. One view is 71045.
CT Head/Brain, Without Contrast
Non-contrast head CT, the emergency workhorse for trauma and stroke rule-out.
MRI Lumbar Spine, Without Contrast
Non-contrast lumbar MRI for radiculopathy and chronic low back workups.
MRI Knee (Any Joint of Lower Extremity), Without Contrast
Non-contrast MRI of a lower-extremity joint. The standard knee MRI code.
Abdominal Ultrasound, Complete
Complete abdominal ultrasound covering all required organs. A limited study is 76705.
Screening Mammography, Bilateral
Annual screening mammogram including CAD. Diagnostic mammography uses 77065/77066.
CT Abdomen and Pelvis, With Contrast
Combined abdomen-pelvis CT with contrast. The combined codes replaced separate billing of each region.
Codes in blue have full detail pages with documentation requirements, billing mistakes, and FAQ.
Radiology billing notes
The TC/26 split rules everything. Freestanding imaging centers usually bill globally; hospitals bill TC while radiologists bill 26. One service, never more than 100% of it.
CT and MRI codes come in with-contrast, without-contrast, and without-then-with families. The code follows what was actually done, and 'with and without' is one code, not two.
Every diagnostic study needs an order from the treating provider, and the interpretation must be a complete signed report. A preliminary note doesn't support the professional component.
Screening mammography (77067) and diagnostic mammography are different codes with different patient cost-sharing. A screening that turns diagnostic mid-visit converts, with modifier GG telling Medicare both happened.
X-ray codes count views: 71045 is one view of the chest, 71046 is two. Billing the two-view code on a single-view study is a small upcode that auditors catch in bulk.
Frequently asked questions about radiology billing
What do modifiers TC and 26 mean on imaging claims?▼
They divide one imaging service between two billers. TC is the technical component, billed by whoever owns the equipment and employs the tech. 26 is the professional component, billed by the physician who interprets and signs the report. Billed globally with no modifier, one party gets both.
Can I bill a CT with contrast and without contrast as two studies?▼
No. When a study is done without contrast and then with it, one combined code covers the whole exam (each CT family has one). Billing the without and with codes separately for one session is unbundling.
What's the difference between screening and diagnostic mammography billing?▼
Intent and cost-sharing. Screening (77067) is the routine annual study and is covered without patient cost-sharing under most plans. Diagnostic (77065 unilateral, 77066 bilateral) works up a finding or symptom and applies normal cost-sharing. A screening that converts the same day is billed with both codes and modifier GG for Medicare.
Sources
- Code set structure and updates: American Medical Association — CPT
- Fee schedule and component billing rules: CMS Medicare Physician Fee Schedule
- How we research and verify: our editorial policy
CPT® is a registered trademark of the American Medical Association. Content on this page is original educational writing, not a reproduction of AMA-copyrighted descriptions. Verify codes and payer rules before billing.