If the provider documents the relationship as the red notes are examples & say such as so it is not an all-inclusive list of applicable diseases.
ICD-10-CM Official Guidelines for Coding and Reporting FY 2022 Page 10
Etiology/manifestation convention (“code first”, “use additional
code” and “in diseases classified elsewhere” notes)
Certain conditions have both an underlying etiology and multiple body system
manifestations due to the underlying etiology. For such conditions, the ICD-10-CM has
a coding convention that requires the underlying condition be sequenced first, if
applicable, followed by the manifestation. Wherever such a combination exists, there is
a “use additional code” note at the etiology code, and a “code first” note at the
manifestation code. These instructional notes indicate the proper sequencing order of
the codes, etiology followed by manifestation.
In most cases the manifestation codes will have in the code title, “in diseases classified
elsewhere.” Codes with this title are a component of the etiology/ manifestation
convention. The code title indicates that it is a manifestation code. “In diseases
classified elsewhere” codes are never permitted to be used as first listed or principal
diagnosis codes. They must be used in conjunction with an underlying condition code
and they must be listed following the underlying condition. See category F02, Dementia
in other diseases classified elsewhere, for an example of this convention.
There are manifestation codes that do not have “in diseases classified elsewhere” in the
title. For such codes, there is a “use additional code” note at the etiology code and a
“code first” note at the manifestation code, and the rules for sequencing apply.
In addition to the notes in the Tabular List, these conditions also have a specific
Alphabetic Index entry structure. In the Alphabetic Index both conditions are listed
together with the etiology code first followed by the manifestation codes in brackets.
The code in brackets is always to be sequenced second.
An example of the etiology/manifestation convention is dementia in Parkinson’s
disease. In the Alphabetic Index, code G20 is listed first, followed by code F02.80 or
F02.81 in brackets. Code G20 represents the underlying etiology, Parkinson’s disease,
and must be sequenced first, whereas code F02.80 and F02.81 represent the
manifestation of dementia in diseases classified elsewhere, with or without behavioral
disturbance.
“Code first” and “Use additional code” notes are also used as sequencing rules in the
classification for certain codes that are not part of an etiology/ manifestation
combination.
See Section I.B.7. Multiple coding for a single condition
Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions, the ICD-10-CM has a coding convention that requires the underlying condition be sequenced first, if applicable, followed by the manifestation. Wherever such a combination exists, there is a “use additional code” note at the etiology code, and a “code first” note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation.
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.
