ICD-10 Code H65.31: Chronic mucoid otitis media, right ear

Key Takeaways

ICD-10 Code H65.31 is a billable/specific ICD-10-CM code for chronic mucoid otitis media, right ear, valid for FY2026 (effective October 1, 2025).

H65.31 describes the right ear only; use H65.32 for the left ear and H65.33 for bilateral disease. Laterality must be documented.

The ICD-9-CM equivalent is 381.20, though ICD-10-CM offers greater specificity by ear side. H65.31 is valid for all HIPAA-covered transactions.

Pabau’s claims management software helps practices attach the correct ICD-10 diagnosis code to each encounter, reducing claim denials.

ICD-10 Code H65.31 is a billable, specific ICD-10-CM code for chronic mucoid otitis media, right ear, within the H65 nonsuppurative otitis media category. Two sibling codes cover the other lateralities: H65.32 for the left ear and H65.33 for bilateral disease.

This reference guide covers the clinical definition of chronic mucoid otitis media, the full H65.31 code details, laterality rules for H65.31 vs H65.32 vs H65.33, ICD-9 crosswalk data, related codes within category H65, and the documentation requirements clinicians need to submit clean claims the first time.

ICD-10 Code H65.31: definition and billable status

ICD-10 Code H65.31 is a billable and specific ICD-10-CM diagnosis code. It describes chronic mucoid otitis media, right ear, a persistent, non-acute middle ear condition involving thick mucoid fluid accumulation without signs of acute bacterial infection.

The code is valid for the FY2026 edition of ICD-10-CM, which became effective on October 1, 2025, and is accepted for all HIPAA-compliant electronic transactions.

The condition is also called glue ear or chronic secretory otitis media in clinical settings, particularly in pediatric and otolaryngology contexts. Clinicians and coders should confirm the diagnosis is chronic (not acute) and limited to the right ear before assigning H65.31.

Pabau’s claims management software attaches the correct ICD-10 code to each encounter at the point of documentation, reducing the risk of selecting the wrong laterality variant on submission.

H65.31 ICD-10-CM code details at a glance

The table below summarizes the key reference data for ICD-10 Code H65.31 that coders need for accurate claim submission.

The CMS ICD-10-CM annual files are the authoritative source for verifying effective dates and code validity each fiscal year.

Clinical description: Chronic mucoid otitis media, right ear

Chronic mucoid otitis media is a type of nonsuppurative otitis media characterized by persistent accumulation of thick, mucoid (glue-like) fluid in the middle ear cavity. Unlike acute otitis media, there is no acute infection, perforation, or purulent discharge.

The fluid is viscous rather than serous, which is why the condition is colloquially called glue ear. According to the WHO ICD-10 classification, this falls within the H65 nonsuppurative otitis media block.

The condition typically results from eustachian tube dysfunction (ETD), which impairs drainage of the middle ear. When the tube fails to equalize pressure or clear secretions, fluid builds up and thickens over time. It is especially common in children but also occurs in adults with allergic rhinitis, adenoid hypertrophy, or recurrent upper respiratory infections.

Key clinical features

• Conductive hearing loss – typically mild to moderate, caused by restricted movement of the tympanic membrane
• Ear fullness or pressure – patients often describe a blocked or “underwater” sensation
• Dull tympanic membrane – grey, amber, or blue on otoscopy; reduced or absent light reflex
• Flat tympanogram – Type B tympanogram is the hallmark finding on tympanometry
• No fever, no otalgia – absence of acute infection signs distinguishes chronic mucoid OM from acute OM
• Recurrent ear infections – chronic fluid can predispose to acute episodes

In children, prolonged conductive hearing loss from chronic effusion can affect speech and language development. Practices offering speech therapy services alongside ENT often coordinate both specialties on the same patient record.

Diagnosis is confirmed by otoscopy, tympanometry, and audiometry. Laterality must be specified: H65.31 applies when the right ear is affected. Use H65.32 for the left ear or H65.33 for bilateral disease. Accurate documentation of these findings in the patient clinical record is essential before assigning the code.

ICD-10-CM coding guidelines for H65.31

The National Center for Health Statistics (NCHS) and the Centers for Medicare and Medicaid Services (CMS) jointly maintain ICD-10-CM coding guidelines. For chronic mucoid otitis media, coders must observe the following rules before assigning ICD-10 Code H65.31.

• Laterality is required. H65.3 (the parent) is not billable on its own. Assign H65.31 (right), H65.32 (left), or H65.33 (bilateral). Missing laterality is a common reason for claim rejection.
• Chronic vs acute distinction. H65.31 is for chronic disease only. Acute mucoid or suppurative OM maps to different codes within H66 or H65.0x. Documentation must clearly state “chronic” or reflect duration consistent with chronic disease.
• Nonsuppurative classification. H65.31 sits in the nonsuppurative block (H65). If the patient has purulent discharge or perforation, a different code applies.
• Excludes notes. H65.3 (and therefore H65.31) carries an Excludes1 note for adhesive middle ear disease (H74.1). Confirm the presentation is chronic mucoid effusion and not chronic adhesive disease before assigning H65.31.
• Additional code for ETD. If eustachian tube dysfunction is documented as a co-existing condition, it may be coded separately with an appropriate H68 code.

Using digital intake forms that capture ear laterality, chronicity, and tympanometry findings at the point of consultation removes ambiguity when a coder later assigns the ICD-10 code. Structured documentation consistently outperforms free-text notes for coding accuracy.

Laterality: H65.31 vs H65.32 vs H65.33

ICD-10 Code H65.31 is one of three laterality variants within the chronic mucoid otitis media subcategory H65.3. Selecting the wrong sibling code is a laterality error and a common reason for administrative denial. The table below shows the full sibling set.

Do not use H65.31 for bilateral disease. Assigning H65.31 when both ears are affected under-specifies the diagnosis and may trigger a review request from the payer. If the record documents bilateral fluid on the same encounter, H65.33 is the correct single code.

Related ICD-10-CM codes and parent category H65

H65.31 sits within the H65 nonsuppurative otitis media category. Understanding the broader code family helps coders navigate related conditions and avoid undercoding or overcoding. The table below maps the most commonly referenced adjacent codes.

For a broader view of all nonsuppurative otitis media codes, the CDC/NCHS ICD-10-CM web tool allows free tabular browsing of the H60-H95 ear disease block. Confirm the fluid type (mucoid vs serous vs purulent) and chronicity before navigating the H65 subcategories.

The same specificity demands apply elsewhere in the H60-H95 chapter: coding H83.19, H80.20, or the right-ear vertiginous syndromes coded to H82.1 also means confirming which ear is affected before the claim goes out.

ICD-9-CM to ICD-10-CM crosswalk: 381.20 to H65.31

Before the ICD-10-CM transition, chronic mucoid otitis media was coded using ICD-9-CM 381.20. This is the primary crosswalk partner for H65.31, though the mapping is not one-to-one. ICD-9 code 381.20 covered chronic mucoid otitis media, simple or unspecified, regardless of ear side, while ICD-10-CM introduced mandatory laterality, splitting 381.20 into three separate codes (H65.31, H65.32, H65.33).

For practices reviewing legacy records or resolving historical claim disputes, this crosswalk is relevant for auditing older encounters. The AAPC ICD-10-CM code lookup tool provides bidirectional crosswalk support for navigating from ICD-9 codes to their ICD-10 equivalents. Correct medical documentation practices at the point of care are the simplest way to ensure laterality is captured before the coding step.

CPT codes commonly billed alongside H65.31

When H65.31 is the primary diagnosis, the associated procedure codes vary depending on the management path taken. Office evaluation and diagnostic testing are the most common procedural pairings, followed by surgical intervention when watchful waiting fails.

Payer-specific policies and medical necessity criteria govern which CPT codes are reimbursable with H65.31; the examples below are general coding practice references, not payer guarantees.

Practices using AI-assisted clinical documentation can capture procedural and diagnostic findings structured enough to support accurate CPT selection at the close of the encounter, reducing the coder’s reliance on reconstructing details from free-text notes.

Some practices bill a brief nurse-only follow-up under 99211 when a patient returns solely for a tube-site or effusion check, rather than a full office visit code.

Documentation best practices for H65.31

Clean claims for ICD-10 Code H65.31 depend on documentation capturing four elements the code requires: laterality, chronicity, fluid type, and absence of acute infection. Missing any one of these creates an ambiguity that forces the coder to default to a less-specific code or delay submission pending clarification.

• State the ear explicitly. Write “right ear” in the assessment, not just “ear” or “bilateral.” Left-right ambiguity is the single most common laterality coding error in otology.
• Confirm chronicity. Use language such as “chronic mucoid effusion” or “persistent middle ear fluid for [duration].” Acute fluid maps to different H65 subcodes.
• Describe the fluid type. “Mucoid” or “glue-like” fluid distinguishes H65.31 from serous otitis media (H65.2x). If fluid appears thin and watery, reconsider the code selection.
• Document the absence of perforation and purulence. A brief note confirming “no tympanic membrane perforation, no purulent discharge” positions the record clearly in the nonsuppurative category.
• Record tympanometric findings. A Type B tympanogram entry in the clinical note adds objective support for the diagnosis.
• Note any associated ETD. If eustachian tube dysfunction is present, document it separately so that an additional H68.x code can be assigned if clinically appropriate.

Practices managing high volumes of ENT encounters can build automated documentation workflows that prompt clinicians for laterality, tympanogram type, and audiometry fields before the note is finalized.

For practices in primary care settings where referral to ENT is common, standardized documentation at the GP level improves the quality of information the specialist receives.

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Treatment options for chronic mucoid otitis media

Treatment selection for chronic mucoid otitis media affects which CPT codes will accompany H65.31 on the claim. The approach depends on patient age, duration of effusion, degree of hearing loss, and whether the condition is recurrent. The American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) provides clinical practice guidelines for otitis media with effusion that inform management decisions.

• Watchful waiting. Recommended for most children for up to three months from diagnosis. No procedure code required; report the office visit (99213/99214) with H65.31.
• Autoinflation. Non-surgical technique to open the eustachian tube. Often trialed before surgical referral.
• Myringotomy with aspiration (CPT 69421). Incision and fluid drainage under general anesthesia. Short-term resolution of effusion.
• Tympanostomy tube insertion (CPT 69436). Grommet placement ventilates the middle ear and prevents fluid re-accumulation. Most common surgical treatment for persistent glue ear.
• Management of underlying ETD. Treating allergic rhinitis, adenoid hypertrophy, or reflux may resolve the underlying cause. Code contributing conditions separately.

Practices managing post-operative ENT patients can use pre- and post-care messaging to automate tube-care instructions and hearing check reminders without manual follow-up. For practices with prescription management workflows, any co-prescribed treatment (such as nasal corticosteroids for ETD) can be documented and tracked within the same patient record.

Conclusion

Laterality errors with chronic mucoid otitis media codes account for a disproportionate share of preventable claim rejections in ENT and primary care billing. Capturing the right ear designation, confirming chronicity, and noting fluid type at the point of documentation means the coder never has to guess when assigning ICD-10 Code H65.31.

Pabau’s claims management and structured clinical notes features help practices build those documentation habits into every ENT encounter. Getting the laterality, chronicity, and fluid type right at the point of care is what keeps H65.31 claims moving on the first submission.

Continue your research

Need a structured clinical record template for ENT encounters? Digital forms allows you to build laterality-aware intake and assessment forms for ear examinations, audiometry findings, and post-procedure instructions.

Coding another condition with strict specificity rules? H57.01 follows the same documentation-first approach this guide covers, for a different anatomical system.

Want to reduce coding errors across all billing workflows? Automated workflows in Pabau can trigger documentation prompts, coding reminders, and pre-submission checks as part of your standard encounter close-out process.

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