ICD-10-CM B99.9 is the diagnosis code for Unspecified infectious disease. This code falls under the section "Other infectious diseases" within Chapter 1 — Certain infectious and parasitic diseases (A00-B99). It is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes. Medical coders and healthcare providers use this code to document and classify diagnoses in electronic health records, insurance claims, and clinical databases.
Always refer to the official ICD-10-CM Tabular List for complete coding guidelines. Ensure documentation supports the specificity of the code selected. When in doubt, consult a certified medical coder or the latest CMS guidelines.
Understanding where B99.9 sits in the ICD-10-CM classification helps ensure proper coding:
Yes, B99.9 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
B99.9 is the ICD-10-CM diagnosis code for "Unspecified infectious disease". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.
The parent code of B99.9 is B99 ("Other and unspecified infectious diseases"). B99.9 provides a more specific classification within this category.
B99.9 is located in Section B99 — "Other infectious diseases" within Chapter 1 of the ICD-10-CM Tabular List.
Use B99.9 when the patients documented diagnosis matches "Unspecified infectious disease" and the clinical documentation supports this level of specificity. Always verify with the latest ICD-10-CM guidelines and payer requirements.
The ICD-10-CM code for Unspecified infectious disease is B99.9.
Yes, B99.9 can be used as a primary diagnosis code since it is billable and specific.
B99.9 is in Chapter 1 of the ICD-10-CM Tabular List.
Yes, B99.9 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.