CurrentEmblemHealthPolicy RP20210015

Manifestation and Secondary Diagnosis Code Guidelines (Commercial & Medicare)

Governs correct coding and billing practices for manifestation and secondary diagnosis codes under EmblemHealth commercial and Medicare products; affects providers submitting claims to EmblemHealth.

Policy Summary

PayerEmblemHealth

PolicyManifestation and Secondary Diagnosis Code Guidelines (Commercial & Medicare)

Policy CodePolicy RP20210015

Change TypeAdministrative formatting

Effective DateAug 31, 2021

Next Review DateN/A

Key ActionDo not report a manifestation code as the only or the first‑listed/principal diagnosis; code the underlying disease first.

SourceLink

POLICY UPDATE CHANGES

Policy content was transferred to an individual company-branded template with no changes to policy title or number.

severalICD-10-CM coding rules summarized

onePrimary policy statement

1Reference sources

Manifestation and Secondary Diagnosis Coding Requirements

Manifestation and secondary diagnosis coding requirements

Trek Health ingests and normalizes Transparency in Coverage data and payer policy updates to give provider organizations a clear view of how commercial reimbursement behaves across markets, payers, and services. Our platform transforms raw payer disclosures into structured intelligence that supports contract evaluation, payer negotiations, and service line strategy. By combining market benchmarks with ongoing policy visibility, Trek helps teams identify variability, risk, and opportunity in commercial reimbursement. The result is faster insight, stronger negotiating positions, and more informed financial decisions.

Requirements for reporting manifestation and secondary diagnosis codes per ICD-10-CM:

ALL of the following

Do not report a manifestation code as the only diagnosis.
Do not report a manifestation code as a first-listed or principal diagnosis; code the underlying disease first.
Manifestation codes are often identified by titles that include 'in disease classified elsewhere' and are listed as secondary codes in the Alphabetic Index; they must be used in conjunction with the underlying condition code.

ALL of the following

For etiology/manifestation conditions, follow the etiology/manifestation convention: the etiology code will carry a 'use additional code' note and the manifestation code will carry a 'code first' note.
'In disease classified elsewhere' codes are not to be used as the first-listed or principal diagnosis; they must follow the underlying condition code.

ALL of the following

The ICD-10-CM Official Guidelines identify which codes may be assigned as principal/first-listed or secondary diagnoses depending on circumstances.
EmblemHealth will deny a claim when a secondary diagnosis is listed as the first-listed or principal diagnosis for any procedure or service.
EmblemHealth may deny the claim and/or recoup payment when coding or billing guidelines and current reimbursement policies are not followed.

ICD-10-CM Manifestation Coding Conventions and Placement

Manifestation code conventionICD-10

In disease classified elsewhere

Manifestation codes that are not to be used as first-listed or principal diagnosis and must be used with an underlying condition code

Manifestation code placement

Placement requirementDo not report a manifestation code as the only diagnosis or as the first-listed/principal diagnosis; code the underlying disease first.

Coding orderUnderlying disease (etiology) must be listed before manifestation codes.

Alphabetic Index guidanceIn the ICD-10-CM Alphabetic Index, manifestation codes are listed as the secondary code in slanted brackets with the underlying disease code listed first.

Definitions: Manifestation and Etiology/Manifestation Convention

Manifestation codes

DefinitionManifestation codes describe the manifestation of an underlying disease, not the disease itself; they should not be reported as the only diagnosis or as the principal/first-listed diagnosis.

Reporting requirementAlways code the underlying condition first and list the manifestation code second.

Policy purposeEnsures accurate claim adjudication and alignment with ICD-10-CM coding conventions.

Etiology/manifestation convention

Etiology/manifestation orderFor etiology/manifestation conditions, code the underlying etiology first (often accompanied by a 'use additional code' note) and the manifestation second (often accompanied by a 'code first' note).

Code title indicatorManifestation codes frequently include 'in disease classified elsewhere' in the code title to indicate they are manifestations, not primary diagnoses.

Restriction on use'In diseases classified elsewhere' codes are not to be used as first-listed or principal diagnosis codes; they must be used with the underlying condition code listed first.

Billing Implications and Denial Risk

Denial Risk

Denial risk when secondary diagnosis is listed as principal/first-listed

EmblemHealth will deny a claim when a secondary diagnosis is first-listed or principal diagnosis for any procedure or service.

Denial Risk

Potential denial or recoupment for noncompliance with coding/billing guidelines

If appropriate coding/billing guidelines or current reimbursement policies are not followed, EmblemHealth may deny the claim and/or recoup claim payment.

Policy Summary

PayerEmblemHealth

PolicyManifestation and Secondary Diagnosis Code Guidelines (Commercial & Medicare)

Policy CodePolicy RP20210015

Change TypeAdministrative formatting

Effective DateAug 31, 2021

Next Review DateN/A

Key ActionDo not report a manifestation code as the only or the first‑listed/principal diagnosis; code the underlying disease first.

SourceLink

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