Is C84 a billable ICD-10-CM code?

No. C84 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does C84 sit in the tabular list?

Neoplasms (C00-D49), in the block Malignant neoplasms of lymphoid, hematopoietic and related tissue (C81-C96).

What cannot be coded together with C84?

C84 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.

C84

C84 — Mature T/NK-cell lymphomas

Non-billable headerICD-10-CM

C84 is a non-billable header ICD-10-CM code for mature t/nk-cell lymphomas. It cannot be billed on its own: choose one of the more specific child codes below.

Excludes1 — never code together

These conditions cannot occur together. Billing both on the same encounter is a denial.

personal history of non-Hodgkin lymphoma (Z85.72)

Other codes that can never be billed with C84

These codes carry an Excludes1 note pointing at C84. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading C84 alone.

C82Follicular lymphoma
C83.0Small cell B-cell lymphoma
C83.3Diffuse large B-cell lymphoma
C83.390Primary central nervous system lymphoma
C84.0Mycosis fungoides
C84.9Mature T/NK-cell lymphomas, unspecified
C86Other specified types of T/NK-cell lymphoma

Risk adjustment

C84 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Code to one of these instead C84

8 child codes. Green means billable.

Questions about C84

Is C84 a billable ICD-10-CM code?: No. C84 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does C84 sit in the tabular list?: Neoplasms (C00-D49), in the block Malignant neoplasms of lymphoid, hematopoietic and related tissue (C81-C96).
What cannot be coded together with C84?: C84 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.