Code: 31231
Description: Nasal endoscopy, diagnostic; unilateral or bilateral (separate procedure)
Context: This code is used when a provider performs a diagnostic nasal endoscopy using an endoscope to examine internal nasal cavities, sinuses, and related structures to evaluate symptoms or pathology.

Guidelines for Proper Use

• Diagnostic, not therapeutic: Use CPT 31231 strictly for diagnostic nasal endoscopy. It is considered a “separate procedure,” meaning it is used when no other major therapeutic procedure is performed during the same session.
• Unilateral or bilateral: The code applies whether the endoscopy is done on one side or both sides of the nasal cavity—there is no distinction in coding.
• Performed when anterior rhinoscopy is inadequate: This procedure is appropriate when standard nasal examination with a speculum cannot fully visualize areas like the middle meatus, sphenoethmoidal recess, or nasopharynx.
• Appropriate setting: CPT 31231 is commonly performed in an office or outpatient setting under topical anesthesia.
• Separate from therapeutic procedures: If any surgical or therapeutic procedure (e.g., sinus surgery, polypectomy) is done during the same encounter, the diagnostic code should not be reported separately if it is considered part of the more extensive procedure.

Common Misuses of 31231

• Bundling with other procedures: Do not report CPT 31231 if it is included in a more comprehensive endoscopic or surgical service performed at the same time.
• Using without documentation: Avoid using this code when the medical record does not clearly state the indication and findings for the endoscopy.
• Incorrect use for partial visualization: Do not use this code when only limited inspection of nasal structures is performed without endoscopic visualization.
• Applying for therapeutic procedures: This code is for diagnostic purposes only and not for endoscopic interventions such as control of bleeding or biopsy.

Notes / Documentation Tips

• Document clear indications: The provider must document the reason for the endoscopy, such as chronic sinusitis, nasal obstruction, epistaxis, nasal polyps, or suspected nasal mass.
• Include anatomical detail: The report should specify which structures were visualized (e.g., turbinates, meatus, sphenoethmoidal recess, septum) and any abnormalities noted.
• State laterality: Indicate whether the exam was unilateral or bilateral for clarity, even though the code itself does not differentiate.
• Check payer policies: Some payers have specific medical necessity requirements for 31231; confirm that documentation supports the need for endoscopy.
• Avoid duplicate reporting: If another endoscopic procedure such as flexible laryngoscopy is performed on the same day, ensure that services are distinct and not considered inclusive under payer rules.