Diagnosis Code Guideline Policies: Manifestation and Secondary Codes

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Diagnosis Code Guideline Policies: Manifestation and Secondary Codes


Date Issued:  06/16/2021


Manifestation Codes

EmblemHealth promotes correct claims coding, including the appropriate use of manifestation codes. Manifestation codes describe the manifestation of an underlying disease, not the disease itself. The ICD-10-CM Manual includes the following instructions for the use of manifestation codes: 

  • 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 backed by blue highlights in the ICD-10-CM Manual. Please reference the legend at the bottom of the page that shows color highlights and definitions. 
  • A “code first underlying disease” instructional note will appear with the underlying disease codes identified. 
  • In the alphabetical index, manifestation codes are listed as the secondary code in slanted brackets with the code for the underlying disease listed first. 

For conditions that have both an underlying etiology and multiple body system manifestations (etiology/manifestation convention): 

  • The etiology code will have a “use additional code” note 
  • The manifestation code will have a “code first” note 
  • In most cases, “in disease classified elsewhere” will be in the code manifestation title 
  • The code title indicates a manifestation code 

“In diseases classified elsewhere” codes are not to be used as first-listed or principal diagnosis code. They must be used in conjunction with an underlying condition code, following the underlying condition.


Secondary Codes  

The ICD-10-CM Official Guidelines for Coding and Reporting identifies which codes may be assigned as principal or first-listed-diagnosis only, secondary-diagnosis only, or principal/first-listed or secondary (depending on the circumstances). EmblemHealth will deny a claim when a secondary diagnosis is first-listed or principal diagnosis for any procedure or service.