Is C84.9 a billable ICD-10-CM code?

No. C84.9 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does C84.9 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 C84.9?

C84.9 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above C84.9 (C84) and apply to it just the same.

C84.9

C84.9 — Mature T/NK-cell lymphomas, unspecified

Non-billable headerICD-10-CM

C84.9 is a non-billable header ICD-10-CM code for mature t/nk-cell lymphomas, unspecified. 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.

mature T-cell lymphoma, not elsewhere classified (C84.4-)

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

NK/T cell lymphoma NOS

Excludes1 inherited from the categories above C84.9

These are not written on C84.9, but they bind it: a note on a category applies to every code beneath it. Billing C84.9 with anything listed here is a denial.

Written on C84 — Mature T/NK-cell lymphomas

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

Other codes that can never be billed with C84.9

These codes carry an Excludes1 note pointing at C84.9. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading C84.9 alone.

C82Follicular lymphoma
C83.0Small cell B-cell lymphoma
C83.3Diffuse large B-cell lymphoma
C86Other specified types of T/NK-cell lymphoma

Risk adjustment

C84.9 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 history

C84.9 has not changed since FY2024 — no addition, revision or deletion across the three most recent ICD-10-CM releases.

Code to one of these instead C84.9

11 child codes. Green means billable.

Related codes at this level

Codes that share C84. If C84.9 is not quite right, the correct code is usually one of these.

Questions about C84.9

Is C84.9 a billable ICD-10-CM code?: No. C84.9 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does C84.9 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 C84.9?: C84.9 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above C84.9 (C84) and apply to it just the same.