C84.99 Mature T/NK-cell lymphomas, unspecified, extranodal and solid organ sites

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

Applies from C84 Mature T/NK-cell lymphomas

Excludes1 (never code together)

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

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

Applicable to

• NK/T cell lymphoma NOS

Excludes1 (never code together)

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

Risk adjustment (HCC)

• CMS-HCC V28: HCC 20 — Lung and Other Severe Cancers
• CMS-HCC V22: HCC 10 — Lymphoma and Other Cancers
• RxHCC V08: HCC 21 — Lymphomas and Other Hematologic Cancers
• ESRD V24: HCC 10

MS-DRG index

Defines the logic of DRG(s) 820-822 in MDC 17.

Approximate ICD-9-CM (GEMs)

• 202.80 Other malignant lymphomas, unspecified site, extranodal and solid organ sites (approximate)

Code annotations containing back-references to C84.99

Back-references to C84

• Type 1 Excludes: C26.1 Malignant neoplasm of spleen ("non-Hodgkin lymphoma (C82-C85)")
• Type 1 Excludes: C76 Malignant neoplasm of other and ill-defined sites ("malignant neoplasm of lymphoid, hematopoietic and related tissue (C81-C96)")
• Type 1 Excludes: C77 Secondary and unspecified malignant neoplasm of lymph nodes ("malignant neoplasm of lymph nodes, specified as primary (C81-C86, C88, C96.-)")
• Type 1 Excludes: C82 Follicular lymphoma ("mature T/NK-cell lymphomas (C84.-)")
• Type 1 Excludes: C83.0 Small cell B-cell lymphoma ("mature T/NK-cell lymphomas (C84.-)")
• Type 1 Excludes: C83.3 Diffuse large B-cell lymphoma ("mature T/NK-cell lymphomas (C84.-)")
• Type 1 Excludes: C86 Other specified types of T/NK-cell lymphoma ("mature T/NK-cell lymphomas (C84.-)")
• Code Also: D47.02 Systemic mastocytosis ("non-Hodgkin lymphoma (C82-C85)")
• Code First: Z15.0 Genetic susceptibility to malignant neoplasm (", if applicable, any current malignant neoplasm (C00-C75, C81-C96)")

Nearby codes

• C84.94 Mature T/NK-cell lymphomas, unspecified, lymph nodes of axilla and upper limb
• C84.95 Mature T/NK-cell lymphomas, unspecified, lymph nodes of inguinal region and lower limb
• C84.96 Mature T/NK-cell lymphomas, unspecified, intrapelvic lymph nodes
• C84.97 Mature T/NK-cell lymphomas, unspecified, spleen
• C84.98 Mature T/NK-cell lymphomas, unspecified, lymph nodes of multiple sites
• C84.99 Mature T/NK-cell lymphomas, unspecified, extranodal and solid organ sites (this code)
• C84.9A Mature T/NK-cell lymphomas, unspecified, in remission