HCPCS code G0279: Diagnostic digital breast tomosynthesis billing guide

Key takeaways

HCPCS code G0279 reports diagnostic digital breast tomosynthesis, or 3D mammography, for one breast or both.

G0279 never stands alone. Report it on the same claim as CPT 77065 for one breast, or CPT 77066 for both.

Medicare Part B covers G0279 only when the record shows a clinical reason for the tomosynthesis.

Screening pairings work differently. CPT 77063 attaches to CPT 77067, and the old Medicare code G0202 was deleted in 2018.

Practice management software like Pabau can flag a G0279 charge that reaches the claim without its primary code.

HCPCS code G0279 is the Medicare add-on code for diagnostic digital breast tomosynthesis, also called 3D mammography. It covers the tomosynthesis component of a diagnostic study, whether the radiologist images one breast or both. As an add-on code, it only exists next to a primary procedure. Submitted on its own, it rejects.

G0279 sits in the HCPCS Level II code set. The Centers for Medicare and Medicaid Services (CMS) maintains that set for services CPT does not describe well. It applies to Medicare and to most Medicaid programs. Commercial payers usually want CPT codes instead, which the crosswalk section below covers.

Digital breast tomosynthesis (DBT) takes several low-dose X-ray images at different angles. Software then reconstructs a three-dimensional view of the breast tissue. When a patient presents with a clinical finding or an abnormal screening result, the radiologist may run DBT alongside standard 2D diagnostic mammography. G0279 captures the tomosynthesis half of that combined study.

How to use G0279 with primary mammography codes

An add-on code needs a primary, or parent, code on the same claim. Two CPT codes qualify as parents for G0279, depending on whether the diagnostic mammography was unilateral or bilateral. Getting that pairing wrong is the most common reason a G0279 claim fails.

Code 77065 covers unilateral diagnostic digital mammography, and 77066 covers the bilateral version. Both are CPT codes maintained by the AMA and recognized by Medicare. G0279 is then listed separately on the same claim to capture the tomosynthesis performed in addition to either study.

G0279 has no place on a screening claim. It cannot ride along with CPT 77067, the bilateral screening mammography code. Screening tomosynthesis has its own add-on, CPT 77063, which Medicare and commercial payers both accept alongside 77067. The older Medicare screening code G0202 was deleted on January 1, 2018, so it is no longer an option either.

The phrase “List separately in addition to” in the official descriptor is the clearest signal here. G0279 supplements a diagnostic study rather than describing it. Any billing system that lets the code travel alone without 77065 or 77066 is set up to produce denials.

Unilateral vs bilateral: A practical note

The descriptor reads “unilateral or bilateral,” so one unit of G0279 covers either case. You do not report two units when tomosynthesis was performed on both breasts. Laterality is carried by the primary code instead, with 77065 for one breast and 77066 for two.

G0279 Medicare fee schedule and reimbursement rates

Medicare sets payment for G0279 each year through the CMS Physician Fee Schedule. Rates split by place of service. Facility rates apply in a hospital outpatient department or ambulatory surgical center, and non-facility rates apply in a physician office or freestanding radiology center. Payment also shifts with your Medicare Administrative Contractor (MAC) jurisdiction and local geographic adjustment.

Rates change every January and vary by locality, so a prior-year fee schedule is not a safe basis for a billing decision. Check the current allowable in the CMS fee schedule search tool or your MAC’s published rates. Do that before you appeal a denial or quote a patient their share.

Practices billing several payers alongside Medicare get more from a dashboard that tracks G0279 acceptance and average payment per payer. That view earns its keep in women’s health.

Medicare coverage and medical necessity requirements

Medicare Part B covers G0279 when the service is medically necessary and properly documented. Coverage is never automatic. The claim needs a clinical indication that justifies tomosynthesis on top of 2D diagnostic mammography.

Coverage criteria and covered diagnosis codes are usually set at MAC level, through Local Coverage Determinations (LCDs). Because LCDs differ by contractor, billing staff should confirm which ICD-10-CM diagnosis codes their own MAC accepts for G0279.

Supporting diagnoses commonly include a breast mass or lump, nipple discharge, an abnormal screening result, and a personal or family history of breast cancer. Check the current list against your MAC’s active LCD before you finalize claims.

If G0279 denials keep landing on unsupported diagnosis codes, compare what your coders submit against that covered list. Pairing the right diagnosis code to the claim at charge capture costs far less than winning it back on appeal.

Documentation requirements for claim support

A G0279 claim with thin documentation will fail medical necessity review even when the code pairing is right. The record has to show why the clinical situation warranted tomosynthesis alongside standard 2D diagnostic mammography.

Required documentation typically includes:

• The clinical indication or symptom prompting the diagnostic study, such as a palpable mass, nipple discharge, or focal asymmetry on prior imaging
• The order or request specifying diagnostic mammography with a tomosynthesis component
• The radiology report confirming both components were performed and interpreted
• ICD-10-CM diagnosis codes that align with an active MAC LCD for G0279 coverage
• Place of service consistent with the provider’s enrollment type, whether facility or non-facility

Capturing all of this at the point of service saves you chasing records months later during an audit or appeal.

G0279 is a useful test of HIPAA-compliant documentation practices. One claim needs three linked pieces: clinical context, an imaging order, and a covered diagnosis code. Practices adding HIPAA-compliant AI tools to speed up dictation still owe the payer those same three elements.

Primary care teams reporting G codes benefit from GP practice software that keeps visits, codes, and claims together.

G0279 vs CPT codes: When each applies

CPT has its own tomosynthesis codes. The AMA introduced 77061, 77062, and 77063 in CPT 2015, effective January 1, 2015. CMS kept G0279 for Medicare rather than adopting them. The 2017 CPT update was a separate change, bringing in 77065, 77066, and 77067 to replace the old 77051 to 77057 series. What remains is a lasting CPT and HCPCS split that still confuses practices billing mixed payers.

Send G0279 to a commercial payer that only takes CPT codes and it denies. Send CPT 77061 to Medicare and the same thing happens. Coders working mixed-payer queues have to confirm each payer’s accepted code set before submission. The AAPC HCPCS code lookup is a quick cross-reference to run against individual payer policy manuals.

The same payer-split question comes up across the rest of HCPCS Level II. Drug codes like J0561 and equipment codes like E0154 each carry their own unit, documentation, and modifier rules.

Common billing errors and how to avoid them

G0279 fails in a small number of predictable ways. The same two or three errors account for most of the rejected claims, so knowing them in advance takes real weight off the billing team.

• Submitting G0279 without a primary code. The most common error by far. G0279 has to appear on the same claim as 77065 or 77066. Without the parent code, the claim rejects as a standalone add-on. Billing systems that enforce code dependency rules catch this on their own.
• Reporting G0279 with a screening code. G0279 belongs with 77065 or 77066 only. Pairing it with CPT 77067 marks the study as screening, and the claim will not stand. G0202 no longer exists, so it cannot serve as a screening partner either.
• Wrong place of service. Both the rate and the claim routing depend on whether the service happened in a facility or non-facility setting. A place-of-service code that does not match the actual setting causes payment discrepancies and can trigger an overpayment review.
• Missing or mismatched diagnosis codes. The ICD-10-CM code on the claim must be covered under the applicable MAC LCD. A diagnosis code outside that list produces a medical necessity denial, however appropriate the service was clinically.
• Billing multiple units for bilateral studies. One unit of G0279 covers unilateral and bilateral procedures alike. Two units on a bilateral case will hit a claim edit or a denial.
• Using G0279 where a payer expects CPT. Commercial payers generally require CPT 77061 or 77062 instead. The code set has to match the payer’s accepted list.

High-volume imaging billers get a lot out of a monthly audit of G0279 denial reasons by payer. Track which errors repeat, and in which payer context. The pattern tells you whether the cause is a system setting, a coder training need, or a payer policy change. Tools built for practice management workflows can surface those denial patterns at procedure code level.

Related mammography billing codes

Diagnostic breast imaging spans a family of codes across both CPT and HCPCS. The table below covers the ones most likely to appear alongside G0279 on a mammography claim or in a crosswalk.

Note that 77061 and 77062 are standalone CPT codes for tomosynthesis used by commercial payers. G0279 is an add-on code used for Medicare diagnostic cases. They describe the same clinical procedure, but they are not interchangeable across payer types.

Add-on pairing is not unique to imaging. Fertility practices meet the same rule when they bill monitoring and retrieval steps in a cycle. The guide to IVF CPT codes works through those pairings in detail.

How claims software keeps G0279 paired with its parent code

Coders usually know the pairing rule. The billing system is where it breaks down, because nothing stops a G0279 charge that reaches the claim with no parent code attached. That makes it a setup problem you can solve once.

Practice management software like Pabau applies that check at charge capture rather than after submission. Pabau’s claims management software warns the biller while the encounter is still open, so the correction takes seconds. The alternative is an appeal that costs more staff time than the payment is worth.

Reporting matters as much as the check itself. Pabau tracks acceptance and denial reasons by procedure code and by payer. That view helps OB/GYN groups and pelvic health practices, which bill imaging next to clinical visits. They can separate a documentation problem from a payer code-set problem quickly.

Keeping the clinical record and the claim in one system helps too. The indication, the diagnosis code, and the submitted charge all come from one place. That removes the transcription errors that creep in between an imaging report and a claim form.

Related HCPCS codes

• HCPCS code G0155 — Clinical Social Worker Home Health Billing
• HCPCS Code G0281 — Electrical stimulation for chronic wound care
• HCPCS code G0299 — Direct skilled nursing services
• HCPCS Code G0316 — Prolonged hospital inpatient

Stop add-on codes like G0279 denying

Pabau’s claims management software checks add-on code pairings at charge capture, so G0279 never reaches a payer without 77065 or 77066. See how it fits your imaging billing workflow.

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Conclusion

G0279 is a small code with a hard dependency. It travels with 77065 or 77066, at one unit whatever the laterality, and only on a diagnostic study. Get those three things right and the code rarely causes trouble.

The durable fix lives in the software rather than in another training session. A claim edit that refuses to release G0279 without its parent code removes that whole error class permanently.

Denial triage is the habit worth building next. Sort every G0279 rejection into missing parent code, medical necessity, or wrong payer code set. Each bucket has one owner and one fix. Book a demo to see how Pabau keeps add-on codes paired and diagnostic imaging claims moving.

Continue your research

Need another HCPCS Level II reference? C1785 shows how device codes are reported inside hospital outpatient claims.

Billing durable medical equipment as well? E0243 walks through the medical necessity documentation Medicare expects for a supply item.

Managing fertility billing alongside imaging? IVF CPT codes explains primary and add-on relationships with the same pairing logic as G0279.

Working with private fee schedules too? Bupa procedure codes covers how a published schedule drives what a payer actually reimburses.

Looking for a broader billing workflow framework? Practice management software features outlines the capabilities that cut claim errors across code families.

Frequently asked questions