31297

🎈 CPT 31297 — Nasal/Sinus Endoscopy, Surgical, with Dilation; Sphenoid Sinus Ostium

Quick Reference

wRVU: 6.44 | Global Period: 090 (90 days) | Assistant Payable: ❌ No | Bilateral Indicator: 1

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📋 Clinical Description

CPT 31297 describes a surgical nasal/sinus endoscopy with dilation of the sphenoid sinus ostium using any dilation method — most commonly balloon catheter dilation (balloon sinuplasty) — performed under endoscopic visualization without tissue removal. The code explicitly includes fluoroscopy when performed as a component of the guidance technique. This code is the sphenoid-specific member of the balloon sinus dilation (BSD) family: 31295 (maxillary), 31296 (frontal), 31297 (sphenoid only), and 31298 (frontal + sphenoid combined); selecting the correct code requires identifying which specific sinus ostium(a) was dilated in the session. The defining characteristic of the 31295-31298 family — and the most critical documentation requirement — is that no tissue is removed: if any tissue is excised, biopsied, or debrided during the same session for the same sinus, the dilation code cannot be reported alongside the tissue-removing endoscopy code for that sinus.

Chronic sphenoidal sinusitis (J32.3) — the prototypical diagnosis driving 31297 — results from persistent mucosal inflammation and ostial narrowing or obstruction of the sphenoid sinus, producing a cycle of impaired drainage, retained secretions, and recurrent infection. The sphenoid sinus is located deep in the posterior skull base, immediately adjacent to the optic nerves, internal carotid arteries, cavernous sinuses, and pituitary gland; sphenoidal disease that progresses without treatment carries disproportionately serious complications relative to more anterior sinus disease. Balloon dilation restores sphenoid ostial patency by fracturing and displacing the surrounding bone and mucosa without tissue removal, preserving mucosal integrity and theoretically reducing surgical morbidity compared to traditional sphenoidotomy (31287-31288). When the disease severity requires tissue removal (polypectomy, debridement, or mucosal stripping), 31287 or 31288 is reported instead of or in addition to 31297 — but never both for the same sphenoid sinus in the same session.

This procedure may be performed in the following clinical contexts:

• Isolated chronic sphenoidal sinusitis with ostial obstruction — Single-sinus disease with endoscopic and imaging evidence of sphenoid ostial narrowing refractory to maximal medical therapy (intranasal steroids, saline irrigation, antibiotics); the prototypical indication for standalone 31297.
• Pansinusitis as part of a multi-sinus balloon dilation session — When multiple sinuses are dilated in the same session (e.g., maxillary + frontal + sphenoid), report 31295, 31296, and 31297 separately for each sinus dilated, using RT/LT modifiers for laterality and -51 or -XS as required; alternatively, 31298 replaces 31296 + 31297 when frontal and sphenoid are both dilated on the same side.
• In-office balloon sinuplasty (IOBS) setting — 31297 is increasingly performed in the office under topical anesthesia as an alternative to ASC-based surgery; prior authorization requirements from commercial payers for IOBS have tightened significantly since 2025; verify payer policy before scheduling as office-based.
• Revision case — restoring sphenoid ostial patency after prior surgery — When prior ethmoidectomy or sphenoidotomy has resulted in ostial scarring or re-stenosis, balloon dilation may be used to re-establish drainage; document the prior surgical history and evidence of re-stenosis for medical necessity.
• Recurrent acute sphenoidal sinusitis (3 or more episodes per year) — When recurrent acute episodes meeting clinical criteria are documented and refractory to medical management; note that ICD-10-CM J01.30 (acute sphenoidal sinusitis) is reported for active acute episodes; the underlying recurrent pattern supports surgical medical necessity even when the active sinusitis has resolved at the time of surgery.

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🔬 Anatomical & Procedural Considerations

Technique Variant	Mechanism / Steps	Coding & Clinical Notes
Balloon Catheter Dilation (Balloon Sinuplasty)	Rigid nasal endoscope introduced; guide catheter advanced to sphenoid ostium under endoscopic and/or fluoroscopic visualization; balloon catheter inflated to 8-12 atm for 5-10 seconds, fracturing/displacing the ostium bony walls; balloon deflated and removed; no tissue excised	Most common technique; fluoroscopy included in 31297 payment when used; operative note must confirm no tissue removal — if any tissue was excised or debrided at the sphenoid, report 31287 or 31288 instead; HCPCS code C1726 (catheter, balloon dilatation, non-vascular) is separately reportable by the facility for the device cost in the ASC setting
Wire-Based / Guidewire-Assisted Dilation	Guidewire advanced into sphenoid sinus under endoscopic visualization to confirm sinus access prior to balloon inflation; image-guidance system may be used	Guidewire access confirmation does not change code selection; image guidance (intraoperative CT navigation) is separately reportable under 61782 when used with endoscopic sinus surgery; confirm payer policy for image guidance billing alongside dilation-only codes
Non-Balloon Dilation (Other Methods)	CPT descriptor reads “with dilation (eg, balloon dilation)” — the “eg” indicates balloon is an example, not a requirement; any dilation method (probe dilation, sinus seeker) qualifies under 31297	Operative note must document dilation of the sphenoid ostium and confirm the method used; confirm that the method chosen truly constitutes ostial dilation (expansion of the ostium) rather than tissue removal
Bilateral Sphenoid Dilation	Same balloon dilation procedure performed on both sphenoid ostia in the same session	Report 31297-50 (single line, 1 unit) for bilateral same-session dilation, subject to 150% bilateral payment adjustment; some MACs prefer two separate lines with RT and LT — verify MAC preference; the sphenoid sinuses are midline-adjacent structures and bilateral dilation is not uncommon in pansinusitis cases

Clinical Pearl

The most critical operative note element for CPT 31297 is explicit confirmation that no tissue was removed from the sphenoid sinus. AMA CPT parenthetical instructions state: “Do not report 31297 in conjunction with 31235, 31287, or 31288 when performed on the same sinus.” If the operative note documents both balloon dilation of the sphenoid ostium AND any sphenoidotomy, polypectomy, or tissue debridement at the sphenoid sinus, the tissue-removing code (31287 or 31288) prevails for that sinus and 31297 cannot be separately reported for the same side. The Medtronic ENT coding reference explicitly states: “CPT codes 31295, 31296, 31297 and 31298 apply to cases in which a balloon catheter is the only instrument or tool used and no tissue is removed.” This is the #1 audit finding for the BSD code family.

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✅ Procedure Includes

• Pre-operative nasal endoscopy to assess the posterior nasal cavity and sphenoid ostium
• Introduction of the rigid nasal endoscope via the naris to the posterior nasal cavity
• Topical and/or infiltration anesthesia preparation of the nasal mucosa
• Guidewire advancement to the sphenoid sinus ostium under endoscopic visualization
• Balloon catheter placement across the sphenoid ostium and balloon inflation for dilation
• Balloon deflation and catheter removal following dilation
• Fluoroscopy for guidance, when performed (included — no separate fluoroscopy code)
• Post-dilation saline irrigation of the sphenoid sinus, when performed
• Documentation of: endoscopic findings, sinus accessed, dilation technique, confirmation of ostial opening, and explicit statement that no tissue was removed

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❌ Excludes / Do Not Report Together

Code	Description	Relationship to 31297
31287	Nasal/sinus endoscopy, surgical, with sphenoidotomy	Mutually exclusive with 31297 for the same sphenoid sinus, same session — per AMA parenthetical instruction; if a sphenoidotomy (tissue removal) is performed at the same sphenoid sinus, 31287 replaces 31297 for that sinus; the two codes represent fundamentally different procedures — dilation only vs. tissue removal
31288	Nasal/sinus endoscopy, surgical, with sphenoidotomy; with removal of tissue from the sphenoid sinus	Mutually exclusive with 31297 for the same sphenoid sinus, same session — per AMA parenthetical; 31288 is the most extensive sphenoid endoscopy code and subsumes dilation when performed in the same sinus
31235	Nasal/sinus endoscopy, diagnostic, with maxillary sinusoscopy	Mutually exclusive with 31297 for the same sphenoid sinus per AMA instruction; 31235 is a sphenoid sinoscopy (diagnostic), which should not be separately reported when a surgical sphenoid dilation is performed on the same sinus
31298	Nasal/sinus endoscopy, surgical, with dilation of frontal and sphenoid sinus ostia (eg, balloon dilation)	31298 is the combination code for frontal + sphenoid dilation on the same side in the same session; if both frontal and sphenoid are dilated on the same side, report 31298 for that side — NOT 31296 + 31297 for the same side; 31297 and 31296 may still be separately reported for the contralateral side if only one or the other is dilated
31296	Nasal/sinus endoscopy, surgical, with dilation of frontal sinus ostium	If frontal AND sphenoid are dilated on the same side, 31298 replaces both 31296 and 31297 for that side; if frontal is dilated on one side and sphenoid on the contralateral side, 31296-RT + 31297-LT may be reported separately with -XS modifier
E/M codes (992xx / 920xx)	Office visit, any level	Separately reportable only when modifier -25 is appended to the E/M code, documenting a significant, separately identifiable E/M service beyond the pre-operative assessment for the sinus surgery; the 90-day global period applies from the date of surgery

Bundling Alert — Global Period is 090 (90 Days), Not 010 or 000

CPT 31297 carries a 90-day global surgical package — one of the longer global periods in ENT surgery — meaning all pre-operative visits (day of or within 24 hours before surgery), intraoperative care, and all routine post-operative care within 90 days are bundled into the single 31297 payment. This includes all post-op nasal debridement visits, saline irrigation follow-ups, and routine endoscopic checks within 90 days. This is a critical distinction from 31237 (polypectomy, biopsy, or debridement — 010 global) and 30110 (simple nasal polypectomy — 010 global); the 90-day global for 31297 is the source of the most common post-operative billing errors in ENT practices. For any E/M visit within the 90-day window for a condition unrelated to the sphenoid sinus dilation, append modifier -24 to the E/M code with explicit documentation of the unrelated nature. For a staged related procedure within the global window (e.g., contralateral side treated separately), append modifier -58 to the new procedure code.

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🌳 Code Tree — Surgery: Nose, Nasal/Sinus Endoscopy - Dilation Family and Related Codes

CPT 31231-31299  Nasal/Sinus Endoscopy
│
├── 31231-31235  Diagnostic Nasal/Sinus Endoscopy
│   ├── 31231  Diagnostic, unilateral or bilateral  (Global: 000)
│   ├── 31233  With maxillary sinusoscopy  (Global: 000)
│   ├── 31235  With sphenoid sinusoscopy  (Global: 000)
│   └── 31239  With dacryocystorhinostomy  (Global: 090)
│
├── 31237-31298  Surgical Nasal/Sinus Endoscopy
│   ├── 31237  Biopsy, polypectomy, or debridement  (Global: 010)
│   ├── 31238  With control of nasal hemorrhage  (Global: 000)
│   ├── 31240  With concha bullosa resection  (Global: 010)
│   │
│   ├── 31253-31259  Ethmoidectomy (Bundled codes)
│   │   ├── 31253  Total ethmoidectomy with frontal sinus exploration  (Global: 090)
│   │   ├── 31254  Partial anterior ethmoidectomy  (Global: 090)
│   │   ├── 31255  Total anterior and posterior ethmoidectomy  (Global: 090)
│   │   ├── 31257  Total ethmoidectomy with sphenoidotomy  (Global: 090)
│   │   └── 31259  Total ethmoidectomy with sphenoidotomy + tissue removal  (Global: 090)
│   │
│   ├── 31267  With maxillary antrostomy; with tissue removal  (Global: 090)
│   ├── 31276  With frontal sinus exploration  (Global: 090)
│   │
│   ├── 31287-31288  Sphenoidotomy
│   │   ├── 31287  With sphenoidotomy  (Global: 090)
│   │   └── 31288  With sphenoidotomy + tissue removal  (Global: 090)
│   │
│   └── 31295-31298  Dilation (Balloon Sinuplasty) Family
│       ├── 31295  Dilation of maxillary sinus ostium  (Global: 090)
│       ├── 31296  Dilation of frontal sinus ostium  (Global: 090)
│       ├── ▶▶ 31297 ◀◀  Dilation of sphenoid sinus ostium  ← YOU ARE HERE  (Global: 090)
│       └── 31298  Dilation of frontal AND sphenoid sinus ostia (same side)  (Global: 090)
│
└── 31299  Unlisted procedure, nasal/sinus endoscopy

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💰 RVU & Reimbursement Profile

Component	Value
Work RVU (wRVU)	6.44 (verify against current CMS MPFS for applicable year)
Global Period	090 (90 days)
Bilateral Indicator	1 — Subject to standard 150% bilateral payment adjustment rules
Assistant Surgeon	❌ Not payable
Co-Surgeon	❌ Not applicable
Team Surgery	❌ Not applicable
PC/TC Split	❌ No — procedure code only (Indicator 0)
Modifier -51 Exempt	No
Device / Supply Code	HCPCS C1726 (Catheter, balloon dilatation, non-vascular) — separately reportable by the ASC or hospital facility for the balloon device cost; not billed by the physician
Anesthesia	Local/topical anesthesia included in the global payment for in-office procedures; monitored anesthesia care (MAC) or general anesthesia separately billable by the anesthesiologist for ASC-based cases

Bilateral Billing Rules

CPT 31297 has a bilateral indicator of 1, meaning it is subject to the standard Medicare 150% bilateral payment adjustment when both sphenoid sinus ostia are dilated in the same session. Report bilateral dilation as 31297-50 on a single line (1 unit) per CMS/NCCI policy, or on two lines with -RT and -LT per some commercial MACs — verify MAC preference. Medicare pays 150% of the single-side fee (100% + 50%). Sphenoid sinuses are midline-adjacent structures; bilateral involvement is common in pansinusitis, and bilateral dilation in the same session is frequently appropriate and separately payable from maxillary or frontal dilation performed on the same date using -XS modifier for distinct structure documentation.

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🏷️ Modifier Reference

Modifier	Name	When to Apply
-50	Bilateral Procedure	Both sphenoid sinus ostia dilated in the same session; most common scenario when pansinusitis involves bilateral sphenoid disease; verify MAC billing format preference
-RT	Right Side	Unilateral right sphenoid sinus ostium dilation; document laterality in the operative note
-LT	Left Side	Unilateral left sphenoid sinus ostium dilation
-XS	Separate Structure	Medicare-preferred alternative to -59 when 31297 is reported alongside other sinus dilation codes (e.g., 31295-RT + 31297-LT) to document distinct anatomic structures; use -XS over -59 for Medicare; use -59 for commercial payers that do not accept -XS
-25	Significant, Separately Identifiable E/M	Applied to the E/M code — not 31297 — when a separately documented office visit with distinct medical decision-making is performed on the same date (uncommon for same-day as surgery; more relevant in pre-op office setting)
-24	Unrelated E/M During Postoperative Period	Applied to the E/M code when a patient returns within the 90-day global window for a condition unrelated to the sphenoid sinus dilation; documentation must clearly state the unrelated nature
-51	Multiple Procedures	When 31297 is performed alongside other surgical procedures (e.g., 31295, 31296, 31254) that are not on the same sphenoid sinus; apply -51 to the lower-valued code(s) in the session
-54	Surgical Care Only	When the operating surgeon will not be providing post-operative care — finalized as a policy expansion in the CY 2025 MPFS Final Rule for all 90-day global packages; apply to 31297 when formal transfer of post-op care to another provider is planned
-55	Postoperative Management Only	Applied by the receiving provider who assumes the post-operative care for the 31297 global period; used in conjunction with -54 on the operative claim
-58	Staged or Related Procedure	Planned return to the OR or office during the 90-day global period for a staged completion or related procedure — e.g., contralateral sphenoid dilation performed as a planned second session; document staged nature in the operative plan
-78	Unplanned Return to OR	Unplanned return to the OR within the 90-day global period for a complication of 31297 — e.g., epistaxis or re-obstruction requiring operative intervention
-79	Unrelated Procedure During Postoperative Period	Unrelated surgical procedure performed during the 90-day global window; appended to the unrelated procedure code
-52	Reduced Services	Procedure partially completed — document reason; e.g., inability to access sphenoid ostium due to anatomic variation requiring partial procedure
-53	Discontinued Procedure	Session stopped due to patient safety concern; document reason thoroughly

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🩺 Common ICD-10-CM Pairings

Primary — Chronic Sphenoidal Sinusitis

ICD-10 Code	Description	HCC?	Clinical Notes
J32.3	Chronic sphenoidal sinusitis	❌ No	Primary diagnosis for isolated sphenoid balloon dilation; “chronic” requires documentation of symptoms persisting ≥ 12 weeks per clinical guidelines; imaging (CT sinus) showing sphenoid mucosal thickening or opacification supports the diagnosis; J32.3 has no laterality axis — right vs. left is documented in the CPT modifier, not the ICD-10 code
J32.4	Chronic pansinusitis	❌ No	Use when all paranasal sinuses are involved — documented on CT and in the clinical note; when pansinusitis is the diagnosis, 31297 may be one of several sinus dilation codes reported in the same session (alongside 31295 and/or 31296); J32.4 supports the medical necessity for multi-sinus balloon dilation
J32.8	Other chronic sinusitis (two or more sinuses, not pansinusitis)	❌ No	Use when two or more sinuses are documented as chronically involved but not all sinuses (not pansinusitis); this is distinct from J32.4; the clinical note must specify which sinuses are involved
J32.9	Chronic sinusitis, unspecified	❌ No	Least specific — use only when the provider’s documentation does not identify the specific sinus involved even after a query attempt; almost never appropriate for 31297 claims since the operative note by definition identifies the sphenoid sinus

Sphenoid Sinus Polyp / Structural Comorbidity

ICD-10 Code	Description	HCC?	Clinical Notes
J33.8	Other polyp of sinus (accessory, ethmoidal, maxillary, sphenoidal)	❌ No	Report as secondary when the provider documents a sphenoidal sinus polyp as a comorbid finding — note that if a sphenoid polyp is removed during the same session, that tissue removal shifts the sphenoid coding to 31287/31288; J33.8 as secondary with 31297 implies the polyp was present but not removed (dilation only)
J34.2	Deviated nasal septum	❌ No	Report as secondary when deviation is documented and contributes to drainage impairment or affects surgical approach; may also support reporting of concurrent 30520 (septoplasty) in the same session with -51
J34.89	Other specified disorders of nose and nasal sinuses	❌ No	Use for documented sinonasal pathology not captured by more specific codes — e.g., ostial stenosis, nasal/sinus scarring — when contributing to the clinical picture driving the dilation

Medical Therapy Failure / High-Risk Population Codes

ICD-10 Code	Description	HCC?	Clinical Notes
J45.909	Unspecified asthma, uncomplicated	❌ No	Chronic rhinosinusitis with nasal polyps is strongly associated with asthma; report when documented as a comorbid condition; query for intermittent vs. persistent and severity for maximum specificity; asthma with CRS is a key indicator of Samter triad — document accordingly if provider describes it
Z87.01	Personal history of pneumonia	❌ No	Occasionally relevant when recurrent lower respiratory infections are driven by uncontrolled upper airway sinonasal disease
J01.30	Acute sphenoidal sinusitis, unspecified	❌ No	Report only when recurrent acute episodes are the documented clinical driver for surgical intervention AND the current encounter represents an acute episode; in most surgical planning encounters, J32.3 (chronic) is appropriate; do not mix J01.- (acute) with the surgical encounter unless the active acute diagnosis is documented at time of surgery

Coding Specificity Reminder

ICD-10-CM J32.3 (chronic sphenoidal sinusitis) has no laterality axis — right vs. left sphenoid disease is not distinguished at the ICD-10-CM code level. Laterality documentation belongs in the operative note and is captured via CPT modifiers -RT, -LT, or -50. This is one of the most commonly queried documentation gaps in rhinology coding — not because the ICD-10 code requires it, but because payer prior authorization systems and medical necessity review tools often require laterality to be documented in the clinical record to support unilateral vs. bilateral procedure billing. Always ensure the CT sinus report and operative note both identify which sphenoid sinus is affected before selecting -RT, -LT, or -50.

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🏥 MS-DRG Considerations (Inpatient)

Inpatient Coding Reminder

CPT 31297 is performed primarily in the outpatient, office, or ASC setting. There are no routine MS-DRG assignments for isolated balloon sphenoid sinus dilation — inpatient admission for this procedure alone is not clinically supported. In rare cases involving complicated sinonasal disease (e.g., intracranial or orbital extension, vision-threatening complications), inpatient admission may occur and ICD-10-PCS coding is assigned. When sphenoid sinus surgery is part of a complex inpatient ENT case, refer to MDC 03 (Diseases and Disorders of the Ear, Nose, Mouth, and Throat) — DRGs 152-156 (Major/Other Head and Neck OR Procedures based on CC/MCC tier). If sphenoid disease has caused intracranial or orbital complications, MDC 01 or MDC 02 may apply depending on the principal diagnosis driving the admission.

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🔧 ICD-10-PCS Equivalents (Inpatient Facility Coding)

Note

Inpatient PCS coding for balloon sphenoid sinus dilation maps to the Dilation (7) root operation in Body System 9 (Ear, Nose, Sinus) — expanding an orifice or the lumen of a tubular body part, consistent with balloon expansion of the sphenoid ostium without tissue removal. This is the key PCS distinction from sphenoidotomy (Excision, root operation B, or Drainage, root operation 9), which involves tissue removal or drainage. The body part values W (Right Sphenoid Sinus) and X (Left Sphenoid Sinus) capture laterality that ICD-10-CM J32.3 does not. The approach character distinguishes non-endoscopic (7, Via Natural or Artificial Opening) from endoscopic-assisted (8, Via Natural or Artificial Opening Endoscopic).

PCS Code	Full Description	Notes
097W7ZZ	Dilation of Right Sphenoid Sinus, Via Natural or Artificial Opening, No Device, No Qualifier	Right sphenoid balloon dilation, standard approach
097X7ZZ	Dilation of Left Sphenoid Sinus, Via Natural or Artificial Opening, No Device, No Qualifier	Left sphenoid balloon dilation, standard approach
097W8ZZ	Dilation of Right Sphenoid Sinus, Via Natural or Artificial Opening Endoscopic, No Device, No Qualifier	Right sphenoid balloon dilation, endoscopic-assisted approach
097X8ZZ	Dilation of Left Sphenoid Sinus, Via Natural or Artificial Opening Endoscopic, No Device, No Qualifier	Left sphenoid balloon dilation, endoscopic-assisted approach

PCS Character Analysis — 097W7ZZ

Position	Character	Value	Definition
1	Section	0	Medical and Surgical
2	Body System	9	Ear, Nose, Sinus
3	Root Operation	7	Dilation (expanding an orifice or the lumen of a tubular body part by stretching the orifice or lumen with intraluminal pressure or by cutting part of the orifice or wall of the tubular body part)
4	Body Part	W	Sphenoid Sinus, Right
5	Approach	7	Via Natural or Artificial Opening (instrument introduced directly into the sinonasal cavity without endoscopic camera visualization as the primary driver)
6	Device	Z	No Device
7	Qualifier	Z	No Qualifier

PCS Root Operation: Dilation (7) vs. Excision (B) vs. Drainage (9)

• Use Dilation (7) when the sphenoid ostium is expanded by balloon or probe displacement — no tissue removed, no fluid aspirated independently; maps to CPT 31297.
• Use Excision (B) when sphenoid sinus tissue (polyp, mucosa, bone) is cut out and sent to pathology — maps to CPT 31288 (sphenoidotomy with tissue removal).
• Use Drainage (9) when the primary goal is aspiration of fluid or purulent material from the sphenoid sinus — maps to CPT 31235 (diagnostic sphenoid sinoscopy with aspiration) or drainage procedures.
• Assign separate PCS code lines for right and left sphenoid when bilateral dilation is performed — PCS has no modifier equivalent; W = Right, X = Left.

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📝 Coding Examples

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Example 1 — ASC: Isolated Right Sphenoid Balloon Dilation with Pre-Op E/M Same Day

Clinical Scenario: A 48-year-old male with a 6-month history of posterior headaches, facial pressure, and two prior courses of antibiotics presents for right sphenoid balloon sinuplasty. CT sinus confirms right sphenoid opacification and ostial narrowing. The ENT surgeon performs a pre-operative evaluation in the pre-op holding area, reviews CT findings, and discusses risks/benefits — documented as a separate E/M note. Under general anesthesia in the ASC, a rigid nasal endoscope is introduced; a guide catheter and balloon are advanced to the right sphenoid ostium under endoscopic and fluoroscopic guidance; the balloon is inflated to 10 atm for 8 seconds; the ostium is visibly widened; balloon removed; sphenoid irrigated with saline. Operative note reads: “Right sphenoid ostial balloon dilation performed; fluoroscopy used; no tissue removed.”

Field	Code	Rationale
CPT 1	31297-RT	Surgical nasal endoscopy with dilation of right sphenoid sinus ostium; RT for right side; operative note confirms fluoroscopy used (included) and no tissue removed
CPT 2	99213-25	Pre-operative E/M; modifier -25 on the E/M code — not 31297 — documenting a separately identifiable evaluation beyond the routine pre-procedure consent discussion; must contain independent history, exam, and MDM
PDx	J32.3	Chronic sphenoidal sinusitis — primary reason for the surgical intervention; documented on CT and in the clinical record with >12-week symptom history

Note

Modifier -25 belongs on the E/M code (99213), not on 31297. For same-day pre-operative E/M services on the day of a procedure with a 090-day global, the documentation must support that the E/M was a distinct, medically necessary service beyond the pre-op assessment inherent to the procedure. In this case, the separate review of CT findings and clinical decision-making note qualifies; a brief consent conversation alone does not.

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Example 2 — ASC: Bilateral Pansinusitis — Multi-Sinus Balloon Dilation, Same Session

Clinical Scenario: A 55-year-old female with CT-confirmed bilateral pansinusitis refractory to 4 months of medical therapy undergoes bilateral multi-sinus balloon sinuplasty. Operative note documents: “Bilateral balloon dilation performed as follows: right maxillary sinus ostium (balloon inflated x1), left maxillary sinus ostium (balloon inflated x1), right frontal recess (balloon inflated x1), left frontal recess (balloon inflated x1), right sphenoid ostium (balloon inflated x1), left sphenoid ostium (balloon inflated x1). Fluoroscopy used throughout. No tissue removed from any sinus.”

Field	Code	Rationale
CPT 1	31295-50	Bilateral maxillary sinus ostium dilation — -50 for bilateral same-session; subject to 150% bilateral adjustment
CPT 2	31296-50-51	Bilateral frontal sinus ostium dilation — -50 for bilateral; -51 as secondary procedure
CPT 3	31297-50-51	Bilateral sphenoid sinus ostium dilation — -50 for bilateral; -51 as tertiary procedure
PDx	J32.4	Chronic pansinusitis — all paranasal sinuses documented as chronically involved bilaterally on CT; supports the medical necessity for all three bilateral dilation codes

Warning

Do NOT replace 31296 + 31297 with 31298 in this scenario. 31298 is the combination code for frontal + sphenoid dilation on the same side — it replaces 31296 and 31297 only when both are performed bilaterally on the same side simultaneously. In a bilateral-of-each scenario (bilateral frontal + bilateral sphenoid), report 31296-50 and 31297-50 separately rather than 31298-50, because the two-sinus combination was not performed as a single combined side procedure. Verify NCCI edit status and AAO-HNS consensus coding guidance when submitting multi-sinus sessions, as the laterality logic for 31298 is a frequent source of claim errors.

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Example 3 — Office (IOBS): Sphenoid + Frontal Same Side → Use 31298; Global Period and Prior Auth Scenario

Clinical Scenario: A 61-year-old male with left-sided chronic sinusitis (sphenoid and frontal) undergoes in-office balloon sinuplasty (IOBS) under topical anesthesia. The operative note documents: “Left frontal recess balloon dilation (balloon inflated x2 to 10 atm); left sphenoid ostium balloon dilation (balloon inflated x1 to 10 atm); fluoroscopy used; no tissue removed.” On Day 45 (within the 90-day global), the patient presents with right-sided facial pressure; CT sinus now shows new right sphenoid disease. The surgeon plans a right sphenoid balloon dilation as a staged procedure.

Field	Code (Office Visit, Day 0)	Rationale
CPT 1	31298-LT	Dilation of left frontal AND left sphenoid ostia in the same session on the same side — 31298 is the correct code for same-side frontal + sphenoid combination; replaces 31296-LT + 31297-LT for the same side
PDx	J32.4	Chronic pansinusitis — left-sided frontal and sphenoid involvement documented

Field	Code (Day 45 Return — In Global)	Rationale
CPT 1	31297-RT-58	Right sphenoid balloon dilation — new, contralateral side not treated at the original session; modifier -58 (staged or related procedure) applied because this is a related sinonasal procedure within the 90-day global window of the original 31298-LT; -58 bypasses the global bundle and opens a new 90-day global from Day 45
PDx	J32.3	Chronic sphenoidal sinusitis — right side, newly documented on CT

Note

Global period reminder: The original 31298-LT on Day 0 opens a 90-day global window through approximately Day 90. The right sphenoid procedure on Day 45 is within that window. Because the right side was not treated at the original session and this represents a planned staged extension of the treatment plan, modifier -58 is appropriate — it signals a staged/related procedure within the global period of the prior surgery, bypasses the bundling, and opens a new 90-day global from the Day 45 service date. Document the staged nature explicitly in the Day 45 operative plan: “Staged right sphenoid balloon dilation; right-sided disease identified post-operatively on CT Day 42; planned completion of bilateral treatment.”

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⚠️ Common Coding Pitfalls

• Reporting 31297 when tissue was also removed from the sphenoid sinus in the same session: The AMA CPT parenthetical instruction is explicit: do not report 31297 in conjunction with 31287 or 31288 when performed on the same sphenoid sinus. If the operative note documents both balloon dilation of the sphenoid ostium AND a sphenoidotomy or tissue debridement at the sphenoid sinus, the tissue-removing code (31287 or 31288) prevails for that sinus and 31297 cannot be additionally reported. The Medtronic coding reference confirms: “CPT codes 31295-31298 apply to cases in which a balloon catheter is the only instrument or tool used and no tissue is removed.” This is the #1 compliance risk for the BSD code family.

• Reporting 31296 + 31297 instead of 31298 for same-side frontal + sphenoid dilation: When both the frontal and sphenoid sinus ostia are dilated on the same side in the same session, 31298 is the correct combination code — not 31296 + 31297 for the same side. Billing both 31296 and 31297 with the same laterality modifier on the same DOS is a CPT coding violation and will fail NCCI edits. 31297 and 31296 may be separately reported only when they are performed on different sides (e.g., right frontal + left sphenoid = 31296-RT + 31297-LT-XS).

• Failing to apply or misapplying the 90-day global period: The 90-day global for 31297 is routinely under-appreciated in ENT practices accustomed to the shorter 010-day global of 31237. Post-operative nasal debridement visits, endoscopic checks, and saline irrigation follow-ups within 90 days are all bundled. Billing a separate E/M or 31231 for routine post-operative endoscopic surveillance within 90 days of 31297 without a modifier creates a recoverable overpayment. The 90-day global applies equally whether the procedure was performed in the office or ASC.

• Ignoring prior authorization requirements for in-office balloon sinuplasty (IOBS): As of 2025, commercial payers have significantly tightened prior authorization for in-office balloon sinuplasty (CPT 31295-31297). Performing 31297 in the office without prior authorization from a commercial payer that requires it will result in claim denial regardless of clinical appropriateness. Verify PA requirements before scheduling IOBS cases.

• Using 31299 (unlisted) when 31298 applies: When a surgeon performs frontal + sphenoid balloon dilation on the same side and is unfamiliar with 31298, the unlisted 31299 is sometimes incorrectly reported. 31298 exists specifically for this combination and must be used when its descriptor matches the service. Reporting 31299 for a service accurately described by an existing CPT code is a CPT reporting violation.

• Failing to document that fluoroscopy was used (or not used): Fluoroscopy is included in the 31297 payment when performed — it is not separately reportable. However, some auditors will look for documentation of the guidance method used in the operative note. “Balloon dilation of sphenoid ostium performed under endoscopic and fluoroscopic guidance” is sufficient; omitting any mention of guidance method weakens the operative note for audit purposes. Conversely, do not separately bill a fluoroscopy code alongside 31297 — it is a bundled component.

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📎 Sources

¹ AMA CPT 2025 Professional Edition — CPT 31297, Surgery: Nose, Nasal/Sinus Endoscopy, Surgical with Dilation; parenthetical instructions for 31295-31298 family · ² CMS 2025 Medicare Physician Fee Schedule Final Rule (CMS-1807-F); CY 2025 MPFS conversion factor $32.3465 · ³ CMS RVU25A Relative Value Files — wRVU (6.44), global period (090), and bilateral indicator data for CPT 31297 · ⁴ AAO-HNS — “CPT for ENT: Balloon Sinus Dilation” (Updated March 2026); coding guidance for 31295-31298 family, parenthetical instructions, and NCCI edit summary · ⁵ AAO-HNS Bulletin — “Consensus Opinion: How to Code Balloon Sinus Dilation” (2013, updated references 2025); same-sinus exclusion rules for 31297 vs. 31287/31288 · ⁶ Medtronic ENT — “Nasal and Sinus Procedures: Commonly Billed Codes” (2025); note that CPT 31295-31298 apply when balloon catheter is the only instrument and no tissue is removed; HCPCS C1726 device billing guidance · ⁷ NCCI Policy Manual Chapter 6 (Surgery: Nose), CMS 2025 — bundling rules for nasal/sinus endoscopy codes including 31297 vs. 31287/31288 mutual exclusivity · ⁸ ICD-10-CM Official Guidelines for Coding and Reporting FY2026 — Chapter 10: Diseases of the Respiratory System, J32 chronic sinusitis coding guidance · ⁹ ICD-10-PCS Official Guidelines for Coding and Reporting FY2026 — Root Operation Dilation (7), Body System 9 (Ear, Nose, Sinus), Body Part W/X (Sphenoid Sinus Right/Left) · ¹⁰ AAPC CPT Code 31297 Reference — aapc.com/codes/cpt-codes/31297 · ¹¹ AAPC Otolaryngology Coding Alert — “Correctly Code This Frontal Sinus and Sphenoid Sinus Balloon Dilation” (2019); 31298 vs. 31296 + 31297 laterality logic · ¹² UHC Provider Policy — Sinus Surgeries and Interventions (2025); CPT 31297 coverage criteria and prior authorization requirements · ¹³ Fallon Health — Balloon Sinus Ostial Dilation Clinical Coverage Criteria (2025); CPT 31295-31298 medical necessity documentation requirements · ¹⁴ MedStar Billing Services — “ENT Billing in 2025: Coding Updates, Reimbursement Guide”; prior authorization trends for in-office balloon sinuplasty · ¹⁵ Palmetto GBA Jurisdiction M — Global Period and Modifier -54/-55 Policy (2024); CY 2025 MPFS Final Rule expansion of modifier -54 for all 90-day global packages · ¹⁶ CMS MPFS Physician Fee Schedule Search — cms.gov/medicare/physician-fee-schedule/search/overview; CPT 31297 payment indicators verification