Healthcare providers typically bill mammography, a vital screening tool for early breast cancer detection, using CPT codes and HCPCS Level II (G codes). However, the correct use of G codes for mammograms—particularly for Medicare beneficiaries—is often a source of confusion for healthcare providers and billing teams.
In this comprehensive guide, we’ll explore:
- The difference between CPT and G codes for mammography
- Specific G codes used for screening and diagnostic mammograms
- CPT codes that apply to commercial payers
- Billing scenarios and documentation tips
- Common errors and how to avoid claim denials
Why Are There G Codes for Mammograms?
CMS (Centers for Medicare & Medicaid Services) uses HCPCS Level II G codes to identify Medicare-specific procedures. For mammography, Medicare requires providers to use G codes instead of certain CPT codes. These G codes offer more specificity for digital mammography and computer-aided detection (CAD), which are now standard practices.
While CPT codes are typically used for commercial insurance, Medicare mandates the use of G codes when billing for screening or diagnostic mammograms.
CPT Codes for Mammography (Commercial Insurance)
For private payers, mammography procedures are generally billed using the following CPT codes:
- 77067 – Screening mammography, bilateral (2-view study of each breast), including CAD when performed.
- 77066 – Diagnostic mammography, bilateral, including CAD when performed.
- 77065 – Diagnostic mammography, unilateral, including CAD when performed.
These codes replaced older codes 77055–77057 and CAD add-on codes 77051–77052 in 2018.
G Codes for Mammography (Medicare Billing)
Medicare rejects CPT codes 77065–77067 for mammography billing.Instead, it requires providers to use the following G codes:
1. G0202
Description: Screening mammography, bilateral (2-view study of each breast), digital, including CAD when performed.
Use: For routine annual breast cancer screening for asymptomatic Medicare patients.
2. G0204
Description: Diagnostic mammography, bilateral, digital, including CAD when performed.
Use: When a Medicare patient requires diagnostic follow-up for an abnormal screening result or presents with breast symptoms.
3. G0206
Description: Diagnostic mammography, unilateral, digital, including CAD when performed.
Use: For Medicare patients needing diagnostic imaging of one breast.
When to Use G Codes vs. CPT Codes
| Payer Type | Screening | Diagnostic (Unilateral) | Diagnostic (Bilateral) |
| Medicare | G0202 | G0206 | G0204 |
| Commercial Payers | 77067 | 77065 | 77066 |
Therefore, knowing your payer is key.Submitting a CPT code to Medicare may result in claim rejection, and vice versa.
Key Billing and Documentation Considerations
1. Screening vs. Diagnostic Mammogram
- Generally, screening mammograms apply to asymptomatic women and Medicare typically allows them once every 12 months for patients over 40.
- Providers use diagnostic mammograms when patients have symptoms, abnormal findings, or a prior history of breast cancer.
Make sure providers clearly document the medical necessity for diagnostic procedures
2. Modifier Use
For cases where a screening turns into a diagnostic exam on the same day:
Use modifier -GG (Performance and payment of a screening mammogram and diagnostic mammogram on the same day).
Use modifier -GH when a diagnostic mammogram is performed in place of a screening due to findings.
Example:
G0202 (screening) + G0204-GG (diagnostic on same day).
3. Frequency and Coverage Rules
Medicare generally covers:
- One screening mammogram every 12 months for women 40 and older.
- One baseline mammogram for women 35–39.
Medicare covers diagnostic mammograms as medically necessary without frequency limitations.
Avoiding Common Coding Errors
Incorrect coding or mismatched modifiers may trigger denials, underpayments, or audit flags. Avoid these common mistakes:
- Using CPT 77067 for Medicare – Medicare requires G0202.
- Missing modifiers when both screening and diagnostic services are provided.
- Incorrect laterality – always confirm whether the mammogram is unilateral or bilateral.
- Inadequate documentation of symptoms or abnormal findings to justify diagnostic codes.
Real-World Coding Scenarios
1: Medicare Screening Mammogram
- Patient: Female, age 65, asymptomatic, annual mammogram
- Correct Code: G0202
2: Medicare Diagnostic Follow-Up
- Patient: Female, age 67, follow-up of prior abnormal mammogram
- Correct Code: G0204 (bilateral diagnostic)
3: Commercial Payer Diagnostic
- Patient: Female, age 45, lump in right breast
- Correct Code: 77065 (unilateral diagnostic)
4: Screening and Diagnostic Same Day
- Patient: Medicare patient, screening scheduled, abnormality detected, additional imaging performedCodes:
- G0202 (screening)
- G0204-GG (diagnostic)
CPT Code for a Screening Mammogram:
If you’ve been advised to have a screening mammogram, you might be wondering about the CPT code for screening mammogram and why it matters. CPT codes, or Current Procedural Terminology codes, are used by healthcare providers and insurance companies to identify medical procedures for billing and record-keeping purposes. Knowing the right mammogram CPT code can help ensure your test is processed correctly and covered by insurance.
What Is a Screening Mammogram?
A screening mammogram is a routine X-ray of the breasts used to detect early signs of breast cancer in women who have no symptoms. It’s an essential preventive health measure, typically recommended for women starting at age 40, though guidelines may vary depending on individual risk factors.
Why Do CPT Codes Matter?
Each medical procedure, including mammograms, has a unique CPT code. These codes help:
- Facilitate insurance claims and reimbursement
- Ensure accurate medical records
- Minimize billing errors
When it comes to mammograms, using the correct CPT code for a mammogram is crucial for smooth insurance processing.
Common CPT Codes for Mammograms
Here are the most widely used CPT codes for mammograms:
- 77067: This is the primary CPT code for screening mammogram. It covers bilateral (both breasts) screening mammography, including computer-aided detection (CAD) when performed.
- 77066: This is used for a diagnostic mammogram (bilateral) when there is a specific breast concern, such as a lump or abnormal imaging result.
- 77065: This code applies to a diagnostic mammogram (unilateral) for a single breast.
For most routine screenings, the screening mammogram CPT code 77067 is the one your healthcare provider will use.
The Difference Between Screening and Diagnostic Mammogram Codes
- Screening Mammogram CPT Code (77067): Used for routine, preventive breast cancer screenings.
- Diagnostic Mammogram CPT Codes (77065 & 77066): Used when there are symptoms or findings that require further investigation.
Furthermore, insurance coverage and out-of-pocket costs may differ depending on whether the mammogram qualifies as screening or diagnostic.
Tips for Patients
- Ask your provider which CPT code they are using for your mammogram. This can help you avoid unexpected charges.
- Verify with your insurance if the screening mammogram is covered as a preventive service, which is often the case under the Affordable Care Act.
- Keep records of your mammogram CPT codes and billing statements for future reference.
Final Thoughts
Understanding the CPT code for screening mammogram can demystify the billing process and help you advocate for your healthcare. The most common mammogram CPT code for routine screening is 77067, but always check with your provider and insurer for the most accurate, up-to-date information.
By staying informed, you can focus on what matters most: your health and peace of mind.