ENT ICD-10-CM
FY 2027 updates.

In this guide

• Chapter 2 · Metastatic neoplasms
• Chapter 5 · Diagnosis in remission
• Chapter 10 · Odontogenic sinusitis
• Chapter 13 · Osteomyelitis
• Chapter 17 · Lynch syndrome
• Chapter 21 · Exposure and history updates

Practice actions · Authoritative references

Chapter 2 Neoplasms

Metastases to the larynx pharynx and oral cavity

Three new codes identify secondary malignancies at these sites. They describe the site to which cancer has spread. The primary malignancy and its status must also be identified when known.

Providers: Name the metastatic site and distinguish it from a new primary cancer. Identify the primary site and whether it is active or previously eradicated. Describe swallowing, voice, speech or airway problems that are evaluated or treated.

Coders: Sequence according to the reason for the encounter. When treatment is directed only to the secondary site, sequence that site first and report the active primary as an additional diagnosis. Apply the separate rules for antineoplastic therapy encounters and complications. Use Z85.- for a former primary only when it has been eradicated, no malignancy remains at that site and no further treatment is directed there. Cervical lymph node metastases require the appropriate lymph node code.

Administrators: Update oncology diagnosis lists and referral templates. Review code mappings so oral cavity metastasis is linked to C79.83, larynx to C78.31 and pharynx to C78.32.

Documentation example: “Metastatic renal cell carcinoma to the larynx; today’s treatment is directed to the laryngeal lesion.” This supports C78.31 for the secondary site. Document the renal primary’s current status separately.

Sources: [1]; [2], PDF p. 2; [3], Section I.C.2. A site-specific code does not independently establish stage, functional impairment or coverage for rehabilitation services.

Chapter 5 Mental Behavioral and Neurodevelopmental Disorders

Gender identity disorder in remission

F64.A provides a specific code for a documented diagnosis in remission. The Tabular inclusion term is “Gender dysphoria, in remission (desistance).”

Providers: Document the diagnosis and remission status when clinically established and relevant to care, including voice or facial surgery evaluation.

Coders: Use F64.A only when supported by the documented diagnosis. Remission cannot be inferred from identity, pronouns, a change in treatment or a history of gender-affirming care.

Administrators: Keep remission diagnoses separate from the history selections in Chapter 21. Update terminology and education in the applicable clinical workflows.

Sources: [1]; [2], PDF p. 5; [3], Sections I.A.19 and I.B.1.

Chapter 10 Diseases of the Respiratory System

Odontogenic sinusitis

New J34.83- codes identify sinusitis arising from a dental source and distinguish the affected sinus.

Providers: State that the sinusitis is odontogenic and identify the involved sinus or sinuses. Describe the dental disease or procedure-related cause when established, relevant findings, and the reason for coordinated dental and ENT treatment.

Coders: Select the complete code supported by the diagnosis. Coexisting dental disease alone does not establish an odontogenic cause. J34.839 applies when the sinus is unspecified; J34.83 is a parent subcategory. Follow applicable additional-code instructions and complication rules when a procedure-related condition is documented.

Administrators: Add dental-source and sinus-specific choices to diagnosis lists and referral templates. Avoid automatic conversion of all chronic sinusitis to these codes.

Documentation example: “Odontogenic maxillary sinusitis associated with an infected maxillary molar.” The documented sinus supports J34.830; report the dental condition when applicable.

Sources: [1]; [2], PDF p. 8; [3], Sections I.B.1, I.B.2 and I.B.16.

Chapter 13 Diseases of the Musculoskeletal System and Connective Tissue

Osteomyelitis of the skull face and sinuses

M86.8X8 expands to complete codes that distinguish skull osteomyelitis from disease involving the face and sinuses. Pott’s puffy tumor is included under M86.8X81.

Providers: Identify the exact bone or site and the osteomyelitis type, including acuity or chronicity when established. Document Pott’s puffy tumor when diagnosed, the organism when known, and associated abscesses or intracranial complications.

Coders: M86.8X8 is no longer a complete reportable code. Use these children when the documented diagnosis is classified to “other osteomyelitis.” A more appropriate osteomyelitis type may lead elsewhere. Review separate pathways for orbital, petrous bone and vertebral disease. Follow M86 instructions for an additional infectious-agent code and major osseous defect when applicable.

Administrators: Replace the former M86.8X8 selection with complete choices. Preserve a workflow for clarifying the site and osteomyelitis type rather than assigning M86.8X89 automatically.

Sources: [1], M86 and M86.8X8; [2], PDF p. 13; [3], Sections I.A.3 and I.B.2.

Chapter 17 Congenital Malformations Deformations and Chromosomal Abnormalities

Inherited cancer predisposition and Lynch syndrome

New category QA1 identifies genetic disorders associated with neoplasms, not elsewhere classified. QA1.7 groups inherited neoplasm predisposition syndromes involving multiple systems. QA1.71 identifies Lynch syndrome.

Providers: Document established Lynch syndrome and the identified pathogenic variant, when known. Record any active cancer, personal cancer history and relevant genetic susceptibility. Include this information when it informs oncology assessment or referral.

Coders: Family history or an abnormal tumor screening result alone does not establish Lynch syndrome. QA1 instructs “Code also,” when applicable, associated genetic susceptibility (Z15.0-), malignancy (C00.0-C96.9) or personal history (Z85.-). This note does not itself set sequencing. The QA1 Excludes2 note permits reporting a separately present MEN syndrome.

Administrators: Update genetics and oncology diagnosis lists and review existing generic susceptibility mappings. QA1 and QA1.7 require a complete diagnosis code.

Sources: [1], QA1 and QA1.71; [2], PDF pp. 16-17; [3], Sections I.A.12 and I.A.17.

Chapter 21 Factors Influencing Health Status and Contact with Health Services

Blast overpressure exposure

New Z77.4- codes distinguish documented or suspected blast overpressure exposure by level. These may be relevant to otologic, hearing or balance evaluations.

Providers: Record the exposure source, circumstances and level when known. Document any diagnosed hearing loss, tinnitus, tympanic membrane injury or other health effect separately.

Coders: Select the complete exposure code supported by the record. Exposure alone does not establish an injury or traumatic brain injury. Z77.4 has no instruction requiring a Y code for location. Apply any relevant external-cause reporting requirements and review the category’s exclusions, including occupational exposure.

Administrators: Add the level-specific options and retain space for the diagnosed condition and exposure circumstances.

Sources: [1], Z77 and Z77.4; [2], PDF pp. 23-24; [3], Sections I.C.20 and I.C.21.

Gender transition and detransition history

Z87.890 expands to complete history codes. Z87.893 adds personal history of gender detransition. These details may inform voice, airway or facial surgery care.

Providers: Document the relevant history and type of transition. Identify prior procedures or hormonal treatment when relevant. Use the patient’s documented history and clinically appropriate terminology.

Coders: Z87.890 is a parent code. Use a supported child code; Z87.893 has a “Code also” instruction for Z87.890-. Apply inherited instructions, including sequencing for a follow-up examination when applicable. History codes do not replace the condition supporting current care. Do not infer detransition or remission from interrupted treatment.

Administrators: Replace Z87.890 in selectable lists. Keep transition history, intersex surgical history, detransition history and a documented remission diagnosis distinct.

Sources: [1], Z87 and Z87.890-Z87.893; [2], PDF p. 24; [3], Sections I.A.17 and I.C.21.

Applying the updates in ENT practice

Use the chapter sections as a documentation and workflow reference. The treating provider establishes the diagnosis; the coder validates the complete code and applies the reporting rules for the setting. New code availability does not establish medical necessity or guarantee payer coverage.

Provider documentation priorities

• Cancer care: State the primary and metastatic sites, whether each malignancy is active or historical, and the condition or site addressed at the visit.
• Sinus and bone disease: Name the affected sinus or bone, document a dental cause when established, and clarify osteomyelitis type and associated complications.
• Shared care: Record a confirmed syndrome, remission status, exposure level or relevant history explicitly. Describe functional effects that are evaluated or treated.

Coder validation priorities

• Locate the diagnosis in the FY 2027 Alphabetic Index or Neoplasm Table, then confirm the complete code and inherited instructions in the Tabular List.
• Check additional-code notes, exclusions and encounter-specific sequencing. Query when the diagnosis, site, cause or disease status is unclear.
• For outpatient and professional reporting, follow the outpatient rules for uncertain diagnoses. Report documented symptoms or findings when a definitive diagnosis has not been established.

Administrator implementation priorities

• Update EHR diagnosis lists, coding systems, referral forms and education. Retire M86.8X8 and Z87.890 as complete claim selections and map to supported child codes.
• Review authorizations, payer edits and diagnosis-to-service mappings. Monitor rejected claims and clarification patterns after implementation, especially new codes and expanded parents.