Question 1

What is ICD-10 code K05?

Accepted Answer

K05 is the ICD-10-CM diagnosis code for Gingivitis and periodontal diseases. It belongs to the ICD-10-CM chapter for diseases of the digestive system (k00-k95). K05 is a non-billable header code that organizes more specific child codes; the actual diagnosis on a claim must use one of those children. K05 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Question 2

Is K05 an HCC code?

Accepted Answer

K05 is a non-billable header code, so it cannot itself be a payment HCC. Header codes organize more specific child codes that share the same root concept; one of those children may map to a payment HCC under the CMS-HCC V28 or V24 risk adjustment model. Coders should select a child code from the K05 hierarchy that matches the documented presentation, then check that specific child for HCC status.

Question 3

Is K05 billable?

Accepted Answer

No. K05 is a header (non-billable) ICD-10-CM code. Header codes sit at a higher level of the diagnosis hierarchy and exist to organize a family of more specific child codes. Per ICD-10-CM coding guidelines, a header code cannot be reported on a claim as the diagnosis, coders must select a billable child code from the K05 hierarchy that matches the highest level of specificity supported by the provider's documentation. Payers reject header codes submitted as the primary diagnosis.

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K05

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K05 ICD-10-CM Code: Gingivitis and periodontal diseases