Correct balloon sinuplasty billing comes down to four answers: which sinus ostium was dilated, the setting, whether FESS touched the same sinus, and how many sides were treated.
The code family is CPT 31295 (maxillary), 31296 (frontal), 31297 (sphenoid) and 31298 (frontal plus sphenoid). Each applies only when a balloon is the sole tool and no tissue is removed.
When these four points are clear and backed by payer criteria and a solid op note, balloon claims are far more likely to pay the first time.
Matching Each Balloon Code to the Sinus Treated
Each code describes balloon sinus ostial dilation through a surgical endoscope, and the sinus decides which one applies:
- CPT 31295: maxillary sinus ostium, transnasal or via the canine fossa
- 31296: frontal sinus ostium
- 31297: sphenoid sinus ostium
- 31298: frontal and sphenoid ostia dilated in the same session
When frontal and sphenoid dilation happen together on one side, report 31298 rather than 31296 plus 31297.
There is no balloon code for the ethmoid sinus. The AAO-HNS coding guidance notes that ethmoid work is reported with ethmoidectomy codes instead.
If any bone or mucosa is removed from the dilated sinus, the sinus surgery code applies instead.
Why Office Rates Dwarf Facility Rates
Place of service changes balloon sinuplasty billing more than any other factor. Office payment includes practice expense for the balloon system, staff and room.
In a hospital or ASC, the physician is paid for professional work only, and the facility bills the device and overhead.
The Medtronic CY2026 coding guide lists these 2026 Medicare national averages for the physician:
| Code | Office | Facility |
|---|---|---|
| 31295 | $1,579 | $135 |
| 31296 | $1,604 | $152 |
| 31297 | $1,566 | $124 |
| 31298 | $2,968 | $216 |
That gap is why in-office balloon dilation draws extra scrutiny, and why a wrong place-of-service code is costly.
Facility claims map to OPPS APC 5155 in 2026. Comparing remits against these rates helps catch ENT underpayments early.
Hybrid Cases: Balloon and FESS Together
Many cases mix balloon dilation on some sinuses with FESS on others. The sinus, not the session, decides what is billable.
A balloon with FESS same sinus is never reported twice. CPT bars pairing:
- 31295 with 31256, 31267 or 31233 on the same maxillary sinus
- 31296 with 31276 on the same frontal sinus
- 31297 with 31287, 31288 or 31235 on the same sphenoid sinus
Cigna policy 0480 treats an adjunct balloon in the same cavity as part of the primary procedure.
Different sinuses are separate services. A left total ethmoidectomy (31255) plus left frontal dilation (31296) supports both codes when no frontal tissue is removed.
Resection codes carry their own pitfalls, covered in our guide to FESS billing errors.
Counting Sides and Sinuses on One Claim
CPT treats sinus endoscopy codes as unilateral, so each side of each sinus is its own service.
For Medicare, modifier 50 bilateral sinus reporting means one line, one unit, with no RT or LT added.
When the code’s bilateral indicator allows it, Medicare generally pays 150% of the one-side rate. Confirm each indicator, since some commercial plans want RT and LT lines instead.
Each different sinus gets its own line, so bilateral maxillary plus left frontal dilation becomes 31295-50 and 31296-LT.
Medicare’s multiple endoscopy rules also reduce payment for the second and later codes.
Missing a second side or sinus is a common leak. Routine ENT charge audits catch these before timely filing closes.
What Payers Require Before Approving Dilation
Commercial plans cover balloon dilation for chronic and recurrent acute rhinosinusitis. Both need symptoms, failed medical therapy and CT proof in each treated sinus. This review step is where balloon sinuplasty billing most often stalls.
Here is how two 2026 policies compare for chronic disease:
| Criterion | Cigna | UHC |
|---|---|---|
| Symptoms | 3+ months | 12+ weeks |
| Medical therapy | 8 weeks | Full courses |
| CT | Each sinus | Each sinus, post-therapy |
| Recurrent acute | 4+ episodes/yr | 4+ episodes/yr |
The UHC Sinus Surgeries and Interventions policy also wants the CT within 12 months and same-side symptoms. Neither plan covers balloon dilation for polyps or tumors.
Diagnosis coding matters too. Chronic rhinosinusitis J32.9 is unspecified, while J32.0, J32.1 and J32.3 name the maxillary, frontal and sphenoid sinuses and better support necessity.
Medicare has no NCD or LCD for this procedure, as the UHC Medicare Advantage ENT policy confirms, though Medicare Advantage plans may apply their own rules.
Many commercial plans require balloon sinuplasty prior authorization, even for office cases, so send therapy dates and the CT report with the request.
Op Note Language That Holds Up on Review
Auditors use the op note to confirm every code and modifier. These five details make that easy.
Each Ostium Named With Its Side
A phrase like “bilateral sinuplasty” leaves the auditor guessing. State each ostium and side, such as “right maxillary and left frontal ostia dilated.”
A Plain Statement That No Tissue Was Removed
Dilation codes require a balloon-only procedure. One sentence confirming no tissue was resected protects the code, especially on hybrid cases.
Device, Inflations and Endoscopic View
Note the balloon system, inflations and the post-dilation endoscopic view to show the work matched the descriptor.
The Clinical Reason for Choosing Balloon
A brief recap of symptom duration, failed therapy and CT findings ties the note to payer criteria without sending reviewers to older visits.
Setting and Anesthesia Recorded Clearly
Record whether the case was done in the office under local anesthesia or in a facility. Any separate same-day visit needs its own note and modifier 25 support.
Where Balloon Sinus Claims Get Rejected
Most balloon sinuplasty billing denials trace back to a few preventable front-end gaps.
Same-Sinus Bundling Edits
A dilation code billed with the same-sinus resection code is denied as included. Scrub hybrid claims by sinus and side.
Authorization That Does Not Match the Case
Approvals often list specific codes and sides. If the case changes, such as an added sphenoid, update the authorization before billing.
Criteria the Chart Cannot Prove
Payers deny when the CT predates medical therapy or therapy dates are missing. Checking the plan policy before scheduling prevents most of these.
Bilateral Lines in the Wrong Format
RT and LT lines sent to a payer expecting -50, or the reverse, can cause a denial or cut payment. Keep payer-specific formats in your scrubber.
Place of Service That Contradicts the Note
An office POS on a case documented in an ASC invites recoupment. Match the POS to where the procedure happened.
Balloon Sinus Claims That Reflect the Care You Provide
Balloon cases look small, but each carries a high-value claim, so coding slips get costly.
Getting your next case right starts with reading it sinus by sinus: name the ostium, confirm no tissue was removed, check for same-cavity FESS, then settle sides and setting.
With payer checks before scheduling, that habit turns balloon sinuplasty billing into steady revenue. For a second look at sinus claims, experienced ENT billing support from MBW RCM can help.
Balloon Sinuplasty Billing FAQs
Can 31296 and 31297 be billed together instead of 31298?
Report 31298 when frontal and sphenoid ostia are dilated on the same side in one session. It replaces the separate pair.
Is there a balloon dilation code for the ethmoid sinus?
No. Ethmoid work is reported with ethmoidectomy codes such as 31254 or 31255, alongside any balloon codes for other sinuses.
Does Medicare cover balloon sinus dilation?
Medicare has no national or local coverage policy for it, so claims rest on medical necessity. Medicare Advantage plans may add criteria.
Can the balloon catheter be billed separately in the office?
The office fee schedule rate already includes practice expense. In balloon sinuplasty billing for hospital outpatient cases, facilities may report a device C-code for Medicare.
Why do in-office balloon claims get extra scrutiny?
The office rate is far higher than the facility rate, so payers watch for place-of-service errors and unmet criteria.