31231

Nasal endoscopy, diagnostic, unilateral or bilateral (separate procedure)

Nasal endoscopy, diagnostic, unilateral or bilateral, is a procedure involving the insertion of a rigid or flexible endoscope into the nasal cavity to directly visualize the anterior nasal cavity, nasal septum, inferior and middle turbinates, olfactory cleft, and the nasopharynx. The procedure is performed for diagnostic purposes to identify abnormalities, evaluate symptoms, assess disease progression, or monitor the effectiveness of medical or surgical treatments. The scope of visualization includes the ostia of the paranasal sinuses (e.g., maxillary, frontal, ethmoid). This code covers both unilateral and bilateral examinations. It is designated as a 'separate procedure', implying it should only be reported when performed independently and not as an integral component of a more extensive surgical procedure (e.g., sinus surgery, polypectomy, biopsy) performed by the same physician on the same day through the same access.

Clinical Indications

  • Evaluation of chronic rhinosinusitis (CRS) or recurrent acute rhinosinusitis to assess mucosal inflammation, polyps, or purulent drainage.
  • Investigation of persistent nasal obstruction, congestion, or difficulty breathing through the nose.
  • Diagnosis and localization of the source of recurrent or severe epistaxis (nosebleeds).
  • Assessment of anosmia (loss of smell) or hyposmia (reduced smell) to identify structural causes.
  • Evaluation of suspected nasal polyps, tumors, or other masses within the nasal cavity or nasopharynx.
  • Investigation of persistent post-nasal drip, unexplained facial pain, or headache suspected to be of sinonasal origin.
  • Identification and removal planning of foreign bodies in the nasal cavity.
  • Post-operative surveillance and evaluation of healing after nasal or sinus surgery (e.g., septoplasty, turbinate reduction, functional endoscopic sinus surgery (FESS)).
  • Suspected cerebrospinal fluid (CSF) rhinorrhea for localization of the leak site.

Procedure Steps

  1. Patient positioning, typically supine or semi-recumbent, with adequate lighting.
  2. Topical application of a vasoconstrictor (decongestant) and/or local anesthetic to the nasal mucosa to improve visualization and patient comfort.
  3. Careful insertion of a rigid or flexible endoscope into one or both nasal passages.
  4. Systematic visualization and examination of the anterior nasal cavity, nasal septum, inferior turbinates, middle turbinates, superior turbinates, olfactory cleft, and nasopharynx.
  5. Detailed inspection of the meatuses and ostia of the paranasal sinuses (e.g., maxillary, frontal, ethmoid) for inflammation, edema, polyps, or discharge.
  6. Documentation of findings, including the presence and characteristics of mucosal changes, polyps, masses, discharge, septal deviations, or other abnormalities. Images or video may be captured.
  7. Withdrawal of the endoscope.

Coding Guidelines

  • CPT code 31231 is designated as a 'separate procedure'. It should not be reported when performed as an integral part of a more extensive surgical procedure (e.g., sinus surgery 31254-31288) performed by the same physician on the same day through the same access. If a diagnostic endoscopy is performed at a separate site or for a distinct diagnostic reason from a subsequent therapeutic procedure, modifiers such as -59, -XU, -XP, -XS, or -XE may be appropriate.
  • The code 31231 encompasses both unilateral and bilateral diagnostic nasal endoscopy. Do not append modifiers -50 (bilateral procedure), -RT (right), or -LT (left) to this code.
  • When a diagnostic nasal endoscopy (31231) leads directly to a surgical endoscopic procedure (e.g., biopsy, polypectomy, or sinus surgery) on the same day, the diagnostic endoscopy is generally considered inclusive to the more comprehensive surgical code and should not be reported separately unless distinct indications or sites apply.
  • Medical record documentation must clearly support the medical necessity for the diagnostic endoscopy, detailing the patient's symptoms, clinical findings, and the specific diagnostic questions being addressed.
  • This procedure typically has a 0-day global period.
  • Do not confuse diagnostic nasal endoscopy (31231) with therapeutic nasal endoscopy procedures which involve intervention (e.g., debridement, lesion removal).
  • If imaging guidance is used during the endoscopy, it should be reported separately with the appropriate radiology code (e.g., 76376, 76377, 76497) if medically necessary and properly documented.

Associated ICD-10 Codes