CPT 77066Radiology

Dx mammo incl cad bi

CPT code 77066 represents a diagnostic mammogram performed on both breasts that includes computer-aided detection (CAD) technology to help identify abnormalities. This is more detailed than a routine screening mammogram and is used when there's a specific concern or symptom.

Showing rates for

National Average

Base Medicare rate

$153.65

This calculator gives a typical-case estimate using standard Medicare modifier rules. Actual payment depends on payer policies, documentation, code-specific CMS status indicators, and locality. Verify before billing.

RVU breakdown

Work RVU

PE RVU (NF)

3.69

MP RVU

0.06

Total RVU

4.75

Conversion factor: 32.3465 · Source: CMS MPFS RVU25A · Confidence: High

NCCI bundling edits

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Billing tips

Verify that both diagnostic intent and bilateral examination are documented before using 77066 instead of unilateral code 77065
Impact: Prevents $20-30 overpayment denials and audits; bilateral code reimburses approximately 30% more than unilateral
Confirm CAD was actually performed and documented; if CAD not used, bill 77056 instead of 77066
Impact: 77066 includes CAD in reimbursement; using wrong code when CAD not performed risks $15-20 overpayment recovery
When screening mammogram (77067) converts to diagnostic on same day, append modifier GG to 77066 and ensure both are supported by documentation
Impact: Proper modifier use allows payment for both services (combined ~$290); missing modifier typically results in denial of diagnostic service
Split billing with modifier 26 (professional) and TC (technical) only when services are performed by separate entities
Impact: Incorrect splitting when global service performed can trigger audits and delay payment by 30-45 days
Link appropriate ICD-10 diagnosis codes that support medical necessity for diagnostic (not screening) mammography
Impact: Screening diagnosis codes will result in automatic denial; proper diagnostic codes (R92.8, N63.x, Z85.3) ensure first-pass payment
Verify patient has not had mammography within past 11 months unless documentation supports medical necessity for earlier repeat
Impact: Medicare and most payers deny mammography performed within frequency limitations without exceptional documentation; avoid $153.65 denial

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Frequently asked questions

What is the difference between CPT 77066 and 77067?

CPT 77066 is for diagnostic bilateral mammography with CAD when there are symptoms or abnormal findings requiring evaluation, reimbursing at $153.65. CPT 77067 is for screening bilateral mammography with CAD in asymptomatic patients for routine cancer detection. The key difference is medical necessity and indication, not the technical procedure.

How much does Medicare pay for CPT 77066 in 2025?

Medicare pays $153.65 for CPT 77066 in 2025 based on the national average non-facility rate. This rate applies to both facility and non-facility settings and is calculated from 4.75 total RVUs multiplied by the 2025 conversion factor of 32.3465.

Can CPT 77066 and 77067 be billed together on the same day?

Yes, when a screening mammogram (77067) reveals an abnormality requiring immediate diagnostic views, you can bill both codes for the same day using modifier GG on the diagnostic code 77066. Documentation must clearly show the screening exam, the finding that prompted conversion, and the additional diagnostic imaging performed.

Does CPT 77066 include computer-aided detection?

Yes, CPT 77066 inherently includes computer-aided detection (CAD) as part of the procedure. If CAD is not performed or available, you must use CPT 77056 instead. The CAD component must be documented in the facility protocol or interpretation report to support billing 77066.

When should I use CPT 77065 instead of 77066?

Use CPT 77065 when only one breast (unilateral) requires diagnostic mammography with CAD, rather than 77066 which is for bilateral examination. Common scenarios include evaluation of symptoms in one breast only, or follow-up of a unilateral finding where the contralateral breast does not require diagnostic imaging.

What diagnosis codes support medical necessity for CPT 77066?

Diagnostic codes that support 77066 include breast lumps (N63.x), abnormal mammogram findings (R92.8), personal history of breast cancer (Z85.3), nipple discharge (N64.52), and breast pain (N64.4). Avoid using screening codes (Z12.31) as these indicate routine screening, not diagnostic examination.

How many RVUs is CPT code 77066 worth in 2025?

CPT 77066 has 4.75 total RVUs in 2025, consisting of 1.0 work RVU, 3.69 practice expense RVU, and 0.06 malpractice RVU. The RVU values are identical for both facility and non-facility settings for this code.