June 26, 2024

Radiology Medical Coding and Billing Guidelines 2026: CPT, ICD-10-CM, Modifiers, X-Ray, CT, MRI & Ultrasound

CPC | Medical Coding | Radiology | Xray
By Janine Mothershed

Radiology Medical Coding and Billing Guidelines 2026: CPT, ICD-10-CM, Modifiers, X-Ray, CT, MRI & Ultrasound

Janine Mothershed CPC, CPC-I

Radiology medical coding requires much more than finding a CPT code for an imaging study. Coders must identify the imaging method, body area, number of views, use of contrast, professional or technical component, medical necessity, and any applicable bundling rules. In addition, the ICD-10-CM diagnosis must support why the imaging service was performed.

For 2026, radiology coders also need to watch annual CPT changes, Medicare payment rules, National Correct Coding Initiative (NCCI) edits, and payer-specific requirements. Therefore, understanding the full radiology coding process can help reduce denials while improving coding accuracy and compliance.

This 2026 guide explains the key CPT, ICD-10-CM, modifier, documentation, and billing rules medical coders and CPC students should know.

Key Takeaways

  • Most radiology services fall within the CPT 70000 series.
  • Always code the imaging study that was actually performed, not simply what was ordered.
  • X-ray code selection often depends on the body area and number of views.
  • CT and MRI coding commonly depends on whether contrast was used.
  • Ultrasound codes may distinguish between complete and limited examinations.
  • Modifier 26 identifies the professional component, while modifier TC identifies the technical component when the CPT code allows component billing.
  • Medical necessity must support the imaging service.
  • Review NCCI edits before separately reporting related imaging procedures.
  • The 2026 CPT code set contains important radiology changes, including new codes involving CTA and CT cerebral perfusion.
  • CPC students should pay special attention to views, contrast, components, anatomy, and radiology terminology.

What Is Radiology Medical Coding?

Radiology medical coding is the process of assigning CPT and ICD-10-CM codes to diagnostic and therapeutic imaging services. Although many people associate radiology only with X-rays, the specialty covers a much wider range of services.

For example, radiology includes:

  • X-rays
  • Computed tomography (CT)
  • CT angiography (CTA)
  • Magnetic resonance imaging (MRI)
  • MR angiography (MRA)
  • Ultrasound
  • Mammography
  • Nuclear medicine
  • Positron emission tomography (PET)
  • Interventional radiology
  • Radiation oncology services

Consequently, radiology coders need strong knowledge of anatomy, medical terminology, imaging techniques, and CPT guidelines. They must also understand how documentation affects code selection.

For a deeper look at imaging methods, see our Medical Coding Types of Radiological Services guide.

What CPT Code Range Is Used for Radiology?

The CPT Radiology section generally includes codes 70010–79999. However, not every imaging-related service appears within one simple code range because certain image-guided procedures and related services may appear elsewhere in CPT.

Broadly, the Radiology section includes:

Category General CPT Area
Diagnostic radiology 70010–76499
Diagnostic ultrasound 76506–76999
Radiologic guidance Within applicable radiology ranges
Breast imaging 77046–77067 and related codes
Radiation oncology 77261–77799
Nuclear medicine 78012–79999

Coders should always verify the current CPT codebook rather than selecting a code from a range alone. Moreover, parenthetical instructions and introductory guidelines can change how a service should be reported.

Understanding X-Ray Medical Coding

X-rays are among the most common radiology services, and they are frequently tested on the CPC exam. Most importantly, coders need to pay attention to the anatomical site and number of views.

For example:

  • 71045 – chest, single view
  • 71046 – chest, 2 views
  • 71047 – chest, 3 views
  • 71048 – chest, 4 or more views
  • 74018 – abdomen, 1 view
  • 73610 – ankle, complete, minimum 3 views

Therefore, never assume that “chest X-ray” provides enough information to select a CPT code. The documentation needs to support the number of views represented by the selected code.

Additionally, laterality may affect claim reporting even when it does not change the base CPT code.

Learn more in our complete Medical Coding and Billing for X-Rays in 2026 guide.

CT Scan Coding

Computed tomography creates cross-sectional images using X-ray technology. When coding CT scans, the body region and contrast status are especially important.

Typically, CPT offers different codes for studies performed:

  • Without contrast
  • With contrast
  • Without contrast followed by contrast

For example, CT of the head or brain may be reported with:

  • 70450 – without contrast
  • 70460 – with contrast
  • 70470 – without contrast followed by contrast

As a result, coders should read the actual imaging report carefully. An order requesting contrast does not prove that contrast was administered.

Additionally, CT angiography involves specific CTA codes and requirements. Do not automatically code a standard CT and CTA separately without checking the CPT guidelines and NCCI edits.

MRI Medical Coding

Magnetic resonance imaging uses a magnetic field and radiofrequency energy rather than ionizing radiation. Still, the coding structure often resembles CT because contrast use can determine code selection.

For example, MRI of the brain may involve:

  • 70551 – without contrast
  • 70552 – with contrast
  • 70553 – without and with contrast

Therefore, documentation should clearly identify whether contrast was administered and whether both pre-contrast and post-contrast imaging occurred when required by the code.

Furthermore, coders should distinguish standard MRI from MRA. Although the technologies are related, the procedures answer different clinical questions and use different CPT codes.

Ultrasound Medical Coding

Ultrasound coding introduces another important distinction: complete versus limited examinations.

For example:

  • 76700 – complete abdominal ultrasound
  • 76705 – limited abdominal ultrasound

A complete ultrasound generally requires documentation of the elements specified by CPT for that examination. Conversely, if the required elements are not documented or only a focused area was examined, a limited code may be appropriate.

Therefore, coders should never choose “complete” simply because the provider documented “abdominal ultrasound.” Review the actual report and CPT requirements.

Our Medical Coding Ultrasound guide provides additional examples and documentation tips.

Nuclear Medicine and PET Coding

Nuclear medicine uses radiopharmaceuticals to evaluate organ function, physiology, and disease. PET imaging also measures metabolic activity and plays an important role in oncology, cardiology, and neurology.

Because these studies can involve radiopharmaceuticals, imaging services, and other separately reportable items, coders must review both CPT and HCPCS Level II requirements. Additionally, payer rules may affect which radiopharmaceuticals or supplies can be reported separately.

For this reason, never assume the imaging CPT code represents every billable item associated with a nuclear medicine service.

Radiology Contrast Coding: With vs. Without Contrast

Contrast is one of the most important concepts in radiology coding. However, contrast rules differ among CT, MRI, and other imaging services.

Coders should determine:

  1. Was contrast actually administered?
  2. What type of contrast was used?
  3. Was the examination performed without contrast only?
  4. Was it performed with contrast only?
  5. Were both pre-contrast and post-contrast images obtained?

For example, an oral contrast agent used during a CT does not necessarily satisfy CPT’s meaning of “with contrast” for code selection. Therefore, review the CPT guidelines for the specific imaging modality rather than assuming every contrast agent changes the code.

Professional, Technical, and Global Radiology Billing

Many radiology procedures contain both professional and technical components.

Technical Component – Modifier TC

The technical component includes resources such as:

  • Imaging equipment
  • Supplies
  • Technologist services
  • Image acquisition

When only the technical component is billed and the CPT code allows component billing, append modifier TC.

Professional Component – Modifier 26

The professional component generally represents the physician’s interpretation and report.

When the physician provides only that portion, append modifier 26 when permitted.

Global Radiology Service

If the billing entity provides both the technical and professional components, the service may be billed globally without 26 or TC, when allowed.

For example, an imaging center performs an eligible radiology study while an outside radiologist interprets it. The imaging center may report the technical component with TC, while the radiologist reports the professional component with 26.

However, not every CPT code can be split this way. Therefore, check the Medicare Physician Fee Schedule and payer requirements before automatically applying these modifiers.

Read our detailed guide to Medical Coding Modifiers TC or 26 for more examples.

Other Common Radiology Modifiers

Radiology coders may encounter several additional modifiers:

  • RT – right side
  • LT – left side
  • 59 – distinct procedural service
  • 76 – repeat procedure or service by the same physician or other qualified healthcare professional
  • 77 – repeat procedure by another physician or other qualified healthcare professional
  • X{EPSU} modifiers when applicable under payer rules

Nevertheless, modifiers should never be added simply to force a claim through an edit. Documentation must support the circumstances represented by the modifier.

In particular, use modifier 59 carefully. If an NCCI edit exists, first determine whether a modifier is permitted and whether the services truly meet the requirements for separate reporting.

ICD-10-CM Diagnosis Coding for Radiology

CPT tells the payer what imaging service was performed. ICD-10-CM helps explain why it was medically necessary.

For example, a patient may undergo imaging because of:

  • R05.3 – chronic cough
  • M25.571 – pain in right ankle and joints of right foot
  • M54.50 – low back pain, unspecified
  • R10.9 – unspecified abdominal pain
  • R51.9 – headache, unspecified

However, coders should assign the diagnosis supported by the documentation and applicable setting-specific ICD-10-CM guidelines. Do not automatically code a suspected condition as confirmed when outpatient rules require coding the signs, symptoms, or established diagnoses instead.

Additionally, a final radiology finding does not always mean the coder can automatically replace the ordering provider’s diagnosis. Coding depends on the setting, documentation, provider reporting, and applicable ICD-10-CM guidelines.

Medical Necessity for Radiology Services

Medical necessity remains a major factor in radiology reimbursement. Therefore, the diagnosis submitted on the claim should support the reason for the imaging study.

For Medicare claims, coders may also need to review:

  • National Coverage Determinations
  • Local Coverage Determinations
  • Medicare Administrative Contractor policies
  • Medicare Physician Fee Schedule indicators
  • NCCI edits

Commercial insurers and Medicare Advantage plans may have additional authorization or coverage requirements. Consequently, checking only the CPT code is not enough to determine whether a service will be reimbursed.

Radiology Documentation Checklist

Before finalizing a radiology claim, verify that the documentation supports:

  • Imaging modality
  • Anatomical site
  • Laterality when applicable
  • Number of views when relevant
  • Complete versus limited study
  • Contrast status
  • Medical necessity
  • Ordering information when required
  • Interpretation and report
  • Repeat study circumstances when applicable
  • Image guidance when separately reportable
  • Any modifier used

Additionally, compare the final performed service with the original order. Coding should reflect what actually occurred.

NCCI Edits and Radiology Bundling

CMS maintains the National Correct Coding Initiative to promote correct coding and prevent inappropriate payment for code combinations that should not normally be reported together.

The 2026 Medicare NCCI Policy Manual includes a dedicated chapter for Radiology Services, covering CPT codes 70000–79999. Therefore, coders working with diagnostic imaging, interventional radiology, nuclear medicine, or radiation oncology should review current NCCI guidance.

For example, image guidance may already be included in some procedure codes. Likewise, certain imaging procedures may overlap or represent components of a more comprehensive service.

Never append modifier 59 simply because two codes trigger an edit. Instead, determine whether the services were distinct and whether CMS permits an NCCI-associated modifier.

Important Radiology Coding Updates for 2026

The 2026 CPT code set became effective January 1, 2026. Across CPT, the AMA added 288 new codes, while radiology-related changes include new and revised services that coders should review before submitting 2026 claims.

Notable radiology-related updates include new Category I coding involving:

  • CTA of the head and neck
  • CT cerebral perfusion
  • Irreversible electroporation
  • Thoracic branch endograft services
  • Prostate biopsy
  • Lower-extremity vascular procedures
  • Radiation oncology treatment delivery
  • Superficial radiation therapy
  • Selected endovascular services

Additionally, emerging technologies continue to produce Category III code changes.

CMS also maintains updated 2026 NCCI guidance and Physician Fee Schedule information. Therefore, practices should verify current CPT codes, edits, payment indicators, and payer policies rather than relying on older radiology coding sheets.

Another Medicare issue involves certain CT services performed on equipment that does not meet applicable NEMA XR-29 standards. Medicare continues to apply a payment reduction to the technical component of affected CT services when the equipment does not meet the required standard.

Common Mistakes to Avoid in Radiology Medical Coding

1. Coding the Ordered Study Instead of the Performed Study

An order may request one service while the final procedure differs. Therefore, code from documentation showing what was actually performed.

2. Missing the Number of X-Ray Views

One-view, two-view, three-view, and complete studies may have different CPT codes. Consequently, count the documented views before selecting the code.

3. Confusing “With Contrast” and “Without and With Contrast”

These descriptions are not interchangeable. Review the imaging sequence and CPT requirements carefully.

4. Reporting a Complete Ultrasound Without Required Documentation

A complete examination requires the elements specified by CPT. If those elements are missing, a limited examination may be more appropriate.

5. Incorrectly Using Modifier 26 or TC

Not every service allows component billing. Therefore, check the applicable payment indicators before appending 26 or TC.

6. Automatically Using Modifier 59

An edit does not automatically justify modifier 59. Documentation must show that the services qualify as distinct under the applicable rules.

7. Ignoring Medical Necessity

A technically correct CPT code can still be denied when the ICD-10-CM diagnosis does not support coverage.

8. Using Outdated CPT Codes

Radiology changes every year. Consequently, always use the current 2026 CPT code set for dates of service in 2026.

CPC Student Tips for Radiology Coding

Radiology questions on the CPC exam often become easier when you identify a few key words before looking up the code.

First, identify the body part. Next, determine the imaging method: X-ray, CT, MRI, ultrasound, nuclear medicine, or another modality.

Then look for:

  • Number of views
  • Laterality
  • Contrast
  • Complete versus limited
  • Professional versus technical component
  • Image guidance
  • Repeat imaging

For X-rays, circle or highlight the number of views. Meanwhile, for CT and MRI questions, pay close attention to “without contrast,” “with contrast,” and “without and with contrast.”

Additionally, learn modifier 26 versus TC early. These modifiers appear frequently in diagnostic-service questions and are easier to answer once you understand the difference between interpreting an image and producing it.

Finally, read the parenthetical notes in your CPT book. The answer may depend on a guideline near the code rather than the code descriptor alone.

Radiology Coding Workflow for 2026

A simple workflow can prevent many radiology coding errors:

Step 1: Identify the imaging modality.

Step 2: Identify the anatomical site and laterality.

Step 3: Determine the number of views or extent of the study.

Step 4: Determine contrast status.

Step 5: Review whether the service was complete, limited, bilateral, or unilateral when applicable.

Step 6: Select and verify the CPT code.

Step 7: Determine whether the claim represents global, professional, or technical billing.

Step 8: Assign the appropriate ICD-10-CM diagnosis.

Step 9: Review NCCI edits and modifier requirements.

Step 10: Verify payer coverage and medical necessity.

Following the same process for each case can make complex imaging reports much easier to code.

Authoritative Radiology Coding Resources

Coders should use current authoritative sources when researching radiology coding questions.

Frequently Asked Questions About Radiology Medical Coding

What CPT codes are used for radiology?

Most radiology services fall within CPT codes 70010–79999, although some imaging-related and image-guided services may appear elsewhere in CPT. Always review the current CPT guidelines and parenthetical instructions before selecting a code.

What is the difference between modifier 26 and modifier TC?

Modifier 26 represents the professional component, which generally includes physician interpretation and reporting. Modifier TC represents the technical component, including equipment, supplies, and technical staff. However, use these modifiers only when the CPT code allows component billing.

How do you choose the correct X-ray CPT code?

Start with the body part and then determine the number of views. Additionally, check laterality and whether CPT describes the examination as complete or by a specific number of views.

How do you code CT and MRI contrast?

Determine whether the imaging was performed without contrast, with contrast, or without contrast followed by contrast. Most importantly, code from the performed service and final report rather than relying only on the original order.

What is the difference between a complete and limited ultrasound?

A complete ultrasound requires the documentation elements specified by CPT for that examination. Conversely, a limited ultrasound examines fewer required elements or focuses on a specific area or clinical concern.

Can modifier 59 be used to unbundle radiology codes?

Sometimes, but only when the NCCI edit permits an associated modifier and the documentation supports truly distinct services. Never use modifier 59 solely to obtain separate payment.

Does Medicare require medical necessity for radiology services?

Yes. Medicare coverage generally requires the service to be reasonable and necessary, and the diagnosis should support the imaging study. In addition, LCDs, NCDs, NCCI edits, and other Medicare policies may affect coverage and payment.

What should CPC students study for radiology coding questions?

Focus on anatomy, number of X-ray views, CT and MRI contrast rules, complete versus limited ultrasound, modifiers 26 and TC, radiology terminology, and CPT parenthetical instructions. Additionally, practice reading short radiology reports so you can quickly identify the details that control code selection.

Coding Clarified Final Thoughts

Radiology medical coding in 2026 requires careful attention to much more than the name of the imaging test. Coders need to identify the modality, anatomy, views, contrast, extent of the examination, professional and technical components, diagnosis, medical necessity, and bundling rules.

Moreover, annual CPT and Medicare changes make current resources essential. By following a consistent coding workflow, reviewing the final documentation, and checking current CPT, NCCI, and payer guidance, medical coders can improve claim accuracy while reducing preventable denials.

For students, radiology is also a valuable CPC exam topic because it reinforces anatomy, CPT navigation, modifiers, and medical necessity. Therefore, learning the logic behind radiology coding is more useful than simply memorizing individual codes.

Radiology Resources
 

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