J33.0 ICD-10 Code: Polyp of Nasal Cavity Billing Guide for ENT

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J33.0 is the ICD-10-CM diagnosis code for polyp of nasal cavity, including choanal polyp and nasopharyngeal polyp. It is a billable, specific code classified under Chapter 10 (Diseases of the Respiratory System) within the J30 through J39 block covering other diseases of the upper respiratory tract. ENT practices use J33.0 to support medical necessity for diagnostic nasal endoscopy, nasal polypectomy, functional endoscopic sinus surgery (FESS), and related procedures. The code applies to polyps originating in the nasal cavity itself, not to polyps arising from the paranasal sinuses, which fall under J33.1 or J33.8.

CPT pairing: J33.0 pairs with CPT 31231 (diagnostic nasal endoscopy), CPT 31237 (nasal endoscopy with removal of tissue), CPT 30110 and 30115 (excision of nasal polyp, simple and extensive), and the FESS codes (31253 through 31276) when polypectomy is performed alongside sinus surgery.

J33.0 vs J33.9: J33.0 specifies a polyp of the nasal cavity. J33.9 is the unspecified nasal polyp code. If the documentation identifies the polyp location as the nasal cavity, septum, or nasopharynx, J33.0 is the correct code. Use J33.9 only when the documentation does not specify the site.

Coexisting conditions: Nasal polyps frequently coexist with chronic sinusitis (J32.-), deviated nasal septum (J34.2), and nasal obstruction (R09.81). All documented conditions should appear on the claim to support the full scope of the procedure and strengthen medical necessity.

What J33.0 Means in ENT Billing

J33.0 identifies a polyp of the nasal cavity in the ICD-10-CM classification system. The code sits in Chapter 10, which covers diseases of the respiratory system, under category J33 that groups all nasal polyp diagnoses. The “polyp of nasal cavity” designation includes choanal polyps, which originate in the nasal cavity and extend into the nasopharynx, and other polypoid tissue arising from the nasal septum, turbinates, or lateral nasal wall.

J33.0 is distinct from J33.1 (polypoid sinus degeneration, also known as Woakes’ syndrome) and J33.8 (other polyp of sinus), which describe polyps originating within the paranasal sinuses rather than the nasal cavity. The distinction matters for coding because the polyp’s point of origin determines which code applies, and because payers use these codes to match the diagnosis against the procedure. A claim that reports J33.0 paired with a maxillary sinus surgery code will raise a medical necessity question if the documentation does not explain why a sinus procedure was performed for a nasal cavity polyp.

The code is fully billable and can serve as the primary diagnosis on professional claims. It supports medical necessity for diagnostic endoscopy, polypectomy, and sinus surgery when the documentation establishes that the polyp is under active evaluation or treatment. At ENT Billing Services, the most common issue we see across the billing companies we vet is the routine use of J33.9 (unspecified) when the operative note or nasal endoscopy report clearly identifies the polyp site as the nasal cavity. That default to the unspecified code invites documentation requests and increases audit exposure. For a look at how ICD-10 code changes are affecting ENT billing, see our coverage of the FY 2027 ICD-10-CM ENT update.

How to Bill J33.0 with ENT CPT Codes

J33.0 is the diagnosis. The CPT code is the procedure. The pairing must reflect what was clinically performed and documented. Nasal polyp procedures in ENT use several CPT code families, and selecting the right one depends on the approach, the extent of the procedure, and whether sinus surgery was performed concurrently.

CPT Code	Descriptor	Use with J33.0	Global Period
31231	Nasal endoscopy, diagnostic	Polyp visualization and assessment	0 days
31237	Nasal/sinus endoscopy with biopsy, polypectomy, or debridement	Endoscopic nasal polypectomy	0 days
30110	Excision nasal polyp(s), simple	Non-endoscopic simple polypectomy	0 days
30115	Excision nasal polyp(s), extensive	Non-endoscopic extensive polypectomy	10 days
31253-31276	FESS codes (ethmoidectomy, maxillary antrostomy, sphenoidotomy, frontal sinusotomy)	When polypectomy includes sinus surgery	10-90 days varies

CPT 31231 is the diagnostic nasal endoscopy code and is the most commonly paired CPT code for J33.0 on evaluation visits. When the endoscopy identifies the polyp but no procedure is performed, 31231 with J33.0 is the correct coding. For a full breakdown of this code, see our CPT code 31231 billing guide, which covers the documentation and billing rules for the most commonly used code in rhinology.

CPT 31237 is the endoscopic polypectomy code. It covers nasal or sinus endoscopy with biopsy, polypectomy, or debridement. When an ENT removes a nasal polyp endoscopically and no concurrent sinus surgery is performed, 31237 with J33.0 is the standard pairing. Note that 31231 (diagnostic endoscopy) is bundled into 31237 and cannot be billed separately during the same session.

CPT 30110 and 30115 cover non-endoscopic nasal polypectomy. These are older codes used for simple and extensive polyp excision performed without endoscopic guidance. They are less commonly billed in 2026 because most polypectomies are now performed endoscopically, but they remain valid codes when the procedure is performed non-endoscopically.

J33.0 and the Nasal Polyp Code Family

Category J33 contains four codes, and selecting the right one depends on whether the documentation identifies the polyp’s anatomical origin.

J33.0 (Polyp of nasal cavity) is the code for polyps originating in the nasal cavity, including choanal polyps and nasopharyngeal polyps. This is the most commonly used code for polyps identified on diagnostic nasal endoscopy.

J33.1 (Polypoid sinus degeneration) covers polypoid changes within the sinuses, including Woakes’ syndrome. This code applies when the documentation describes diffuse polypoid degeneration of the sinus mucosa rather than a discrete polyp.

J33.8 (Other polyp of sinus) is for polyps originating within a specific paranasal sinus (maxillary, ethmoid, sphenoid, or frontal) that do not meet the J33.1 criteria. When the operative note describes a polyp arising from the maxillary sinus ostium or ethmoid sinus, J33.8 is typically more accurate than J33.0.

J33.9 (Nasal polyp, unspecified) is the fallback code for polyps without a documented site of origin. Use it only when the documentation genuinely does not specify whether the polyp is nasal cavity or sinus in origin.

Nasal polyps frequently coexist with chronic sinusitis (J32.9), deviated nasal septum (J34.2), and nasal congestion (R09.81). All documented coexisting conditions should appear on the claim. A polypectomy claim with only J33.0 as the diagnosis may be technically accurate, but adding J32.9 for the coexisting chronic sinusitis strengthens the medical necessity justification and provides the payer with the full clinical picture that supports the procedure.

Documentation Requirements for J33.0

The operative report or nasal endoscopy note is the document that supports J33.0 on the claim. Documentation that does not describe the polyp location, size, or clinical impact will invite a denial or a documentation request from the payer.

Polyp site must be specified. J33.0 requires that the documentation identify the polyp as originating in the nasal cavity, on the nasal septum, from a turbinate, or in the nasopharynx (choanal polyp). If the note says “nasal polyp” without specifying the site, the code defaults to J33.9, which weakens the claim and raises audit exposure.

Laterality should be documented. While J33.0 does not carry laterality in the code itself, the operative note should specify whether the polyps are unilateral or bilateral and which side is affected. Laterality affects procedure coding, especially when bilateral endoscopic polypectomy is performed.

Size and extent description. The note should characterize the polyps: are they pedunculated or sessile, isolated or diffuse, obstructive or non-obstructive? This detail supports the choice between simple (30110) and extensive (30115) polypectomy codes and establishes medical necessity for more extensive procedures like FESS.

Clinical impact documented. The note should describe how the polyps affect the patient: nasal obstruction, anosmia, recurrent sinusitis, mouth breathing, sleep disruption. This clinical impact is what establishes medical necessity beyond the existence of the polyp itself.

One pattern we see frequently across the ENT billing companies we vet is the operative note describing diffuse polyposis with sinus involvement, but the biller coding only J33.0 without the chronic sinusitis codes. That omission understates the clinical complexity of the case and can result in the payer questioning why FESS was performed for a simple nasal cavity polyp.

Common J33.0 Billing Mistakes

These are the errors that cause the most nasal polyp denials across ENT practices.

Defaulting to J33.9 when the documentation supports J33.0. If the note describes a polyp of the nasal cavity, middle meatus, or nasopharynx, J33.0 is the correct code. Using J33.9 when a site-specific code is supported is a coding error that increases audit exposure.

Billing 31231 alongside 31237. Diagnostic nasal endoscopy (31231) is bundled into endoscopic polypectomy (31237). Billing both on the same date of service will be denied as a bundling violation. The endoscopy performed to visualize the polyp before removing it is included in the polypectomy code.

Not coding coexisting conditions. A nasal polyp claim that lists only J33.0 without the coexisting chronic sinusitis, deviated septum, or nasal obstruction codes misses the opportunity to strengthen medical necessity and may trigger a payer request for additional documentation to justify a more complex procedure.

Billing 30110 or 30115 with FESS codes. When polypectomy is performed as part of a FESS procedure, the polypectomy is generally included in the FESS code. Billing a simple polypectomy alongside a total ethmoidectomy on the same side will trigger a bundling edit.

Missing the modifier 25 E/M when a separately identifiable evaluation was performed. When the ENT evaluates the patient, makes a clinical decision, and performs endoscopy or polypectomy in the same visit, the E/M is separately billable with modifier 25 if the documentation supports a significant, separately identifiable service. For the latest on how modifier 25 reimbursement is changing for ENT, see our coverage of the ENT modifier 25 payment cut for 2027.

In our experience matching ENT practices with billing partners, the practices with the lowest polyp claim denial rates are the ones that build a two-step check into every nasal polyp claim: confirm the polyp site supports J33.0 over J33.9, and confirm all coexisting conditions from the note appear on the claim. For practices that also perform septoplasty alongside polypectomy, our CPT 30520 septoplasty billing guide covers the code that frequently appears on the same claim as the polypectomy.

Frequently Asked Questions

Next Steps

Need the full billing guide for the diagnostic nasal endoscopy code? See our breakdown of CPT code 31231 for the code that launches most nasal polyp workups.

Treating coexisting chronic sinusitis alongside nasal polyps? Our guide on ICD-10 code J32.9 (chronic sinusitis) covers the diagnosis code that most frequently appears alongside J33.0 on the same claim.

Performing septoplasty alongside polypectomy? See our CPT 30520 septoplasty billing guide for the procedure code that often pairs with polypectomy when a deviated septum is contributing to the obstruction.

Ready to hand ENT billing off to a team that knows rhinology coding, FESS bundling rules, and payer-specific documentation requirements? Get matched with vetted ENT billing companies, free.