C84.0 — Mycosis fungoides
Is C84.0 billable?
No — C84.0 is a non-billable header code. C84.0 groups more specific codes and cannot be submitted on a claim. A valid ICD-10-CM code must be reported at the highest level of specificity available in its branch. Select one of the 11 billable codes beneath C84.0.
Billable codes under this header
- C84.00Mycosis fungoides, unspecified site
- C84.01Mycosis fungoides, lymph nodes of head, face, and neck
- C84.02Mycosis fungoides, intrathoracic lymph nodes
- C84.03Mycosis fungoides, intra-abdominal lymph nodes
- C84.04Mycosis fungoides, lymph nodes of axilla and upper limb
- C84.05Mycosis fungoides, lymph nodes of inguinal region and lower limb
- C84.06Mycosis fungoides, intrapelvic lymph nodes
- C84.07Mycosis fungoides, spleen
- C84.08Mycosis fungoides, lymph nodes of multiple sites
- C84.09Mycosis fungoides, extranodal and solid organ sites
- C84.0AMycosis fungoides, in remission
C84.0 at a glance
| Code | C84.0 |
|---|---|
| Description | Mycosis fungoides |
| Billable | No — header code |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
How is C84.0 listed in the Alphabetic Index?
These are the routes through the Alphabetic Index that lead to C84.0. They show the wording a clinician may have documented, which often differs from the Tabular description.
- Mycosis, mycotic › fungoides
Excludes1 — never code together
The conditions below can never be reported together with C84.0 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
- peripheral T-cell lymphoma, not elsewhere classified (C84.4-)
Excludes1 — never code together — inherited from C84
The conditions below can never be reported together with C84.0 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
- personal history of non-Hodgkin lymphoma (Z85.72)
Excludes2 — not included here — inherited from C81-C96
The conditions below are not part of C84.0, but a patient may have both at the same time. When documentation supports it, C84.0 and the excluded code may both be reported.
What codes fall under C84.0? (11)
- C84.00Mycosis fungoides, unspecified site
- C84.01Mycosis fungoides, lymph nodes of head, face, and neck
- C84.02Mycosis fungoides, intrathoracic lymph nodes
- C84.03Mycosis fungoides, intra-abdominal lymph nodes
- C84.04Mycosis fungoides, lymph nodes of axilla and upper limb
- C84.05Mycosis fungoides, lymph nodes of inguinal region and lower limb
- C84.06Mycosis fungoides, intrapelvic lymph nodes
- C84.07Mycosis fungoides, spleen
- C84.08Mycosis fungoides, lymph nodes of multiple sites
- C84.09Mycosis fungoides, extranodal and solid organ sites
- C84.0AMycosis fungoides, in remission
How long has C84.0 existed?
C84.0 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.
Which codes are confused with C84.0?
ICD-10-CM declares these codes mutually exclusive with C84.0 — exactly one of each pair can be correct for a given encounter.
Which conditions are coded to C84.0?
What other codes are in the C84 family? (7)
- C84.1Sezary diseasenot billable
- C84.4Peripheral T-cell lymphoma, not elsewhere classifiednot billable
- C84.6Anaplastic large cell lymphoma, ALK-positivenot billable
- C84.7Anaplastic large cell lymphoma, ALK-negativenot billable
- C84.ACutaneous T-cell lymphoma, unspecifiednot billable
- C84.ZOther mature T/NK-cell lymphomasnot billable
- C84.9Mature T/NK-cell lymphomas, unspecifiednot billable