ICD-10-CM C84.0 is the diagnosis code for Mycosis fungoides. This code falls under the section "Malignant neoplasms of lymphoid, hematopoietic and related tissue" within Chapter 2 — Neoplasms (C00-D49). It is a non-billable/non-specific ICD-10-CM code that should not be used for reimbursement. A more specific sub-code is required for billing. Medical coders and healthcare providers use this code to document and classify diagnoses in electronic health records, insurance claims, and clinical databases.
The following conditions should never be coded at the same time as C84.0. They are mutually exclusive:
Understanding where C84.0 sits in the ICD-10-CM classification helps ensure proper coding:
No, C84.0 is a non-billable/non-specific code. You should use a more specific sub-code for billing and reimbursement.
C84.0 is the ICD-10-CM diagnosis code for "Mycosis fungoides". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.
The parent code of C84.0 is C84 ("Mature T/NK-cell lymphomas"). C84.0 provides a more specific classification within this category.
C84.0 is located in Section C81-C96 — "Malignant neoplasms of lymphoid, hematopoietic and related tissue" within Chapter 2 of the ICD-10-CM Tabular List.
C84.0 has 11 sub-code(s) that provide more specific detail: C84.00, C84.01, C84.02, C84.03, C84.04 and more.
Use C84.0 when the patients documented diagnosis matches "Mycosis fungoides" 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 Mycosis fungoides is C84.0.
No, C84.0 is non-billable. Use a more specific sub-code for primary diagnosis billing.
C84.0 is in Chapter 2 of the ICD-10-CM Tabular List.
Type 1 Excludes for C84.0 include: peripheral T-cell lymphoma, not elsewhere classified (C84.4-).
Yes, C84.0 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.