C82.18 Follicular lymphoma grade II, lymph nodes of multiple sites

ICD-10-CM Code C82.18: Follicular lymphoma grade II, lymph nodes of multiple sites

ICD-10-CM code C82.18 identifies follicular lymphoma grade II located in the lymph nodes of multiple sites. The terminology record classifies this concept as an active neoplastic process. This code is distinct from related follicular lymphoma diagnoses and appears in specific Medicare articles concerning hematopoietic cell transplantation and minimal residual disease testing. 1 4 5

Plain-language overview

Lymphoma is a cancer of the lymph system, and non-Hodgkin lymphomas begin when a type of white blood cell, called a T cell or B cell, becomes abnormal. 6

What this code represents

The official display label for ICD-10-CM code C82.18 is follicular lymphoma grade II, lymph nodes of multiple sites, and the terminology record designates its status as active. 1

The semantic type assigned to the C82.18 concept within the ICD-10-CM terminology is a neoplastic process, and its parent concept is C82.1, follicular lymphoma grade II. 1

Coding details

Code C82.18 is listed alongside C82.19, which denotes follicular lymphoma grade II at extranodal and solid organ sites, establishing a distinction between nodal and extranodal locations. 4 5

The C82.18 code is one of multiple specific billing codes for follicular lymphoma across various grades and sites, including grade I, grade III, and unspecified designations affecting multiple lymph node regions. 3

Documentation considerations

The official terminology record for C82.18 specifies the neoplastic process as follicular lymphoma grade II located in the lymph nodes of multiple sites, distinguishing it from the C82.19 code for extranodal and solid organ sites. 1 4

Coverage and utilization context

The C82.18 code appears in a Medicare article addressing allogeneic hematopoietic cell transplantation for primary refractory or relapsed Hodgkin and non-Hodgkin lymphoma with B-cell or T-cell origin. 4

The C82.18 code also appears in a separate Medicare article concerning minimal residual disease testing for cancer, though the source text does not state any specific coverage conclusions or rules tied to this inclusion. 5

What the sources add

The National Cancer Institute record provides the authoritative structural definition for C82.18, while the Medicare articles list the code alongside related diagnoses within documents addressing hematopoietic cell transplantation and minimal residual disease testing. 1 4 5

Sources

1. ICD-10-CM C82.18 terminology record — National Cancer Institute Enterprise Vocabulary Services; accessed 2026-07-27.
2. Bookshelf — ncbi.nlm.nih.gov; accessed 2026-07-27.
3. Phecode 202 · Cancer PRSweb — csg.sph.umich.edu; accessed 2026-07-27.
4. Article - Billing and Coding: Allogeneic Hematopoietic Cell Transplantation for Primary Refractory or Relapsed Hodgkin and Non-Hodgkin Lymphoma with B-cell or T-cell Origin (A59311) — cms.gov; accessed 2026-07-27.
5. Article - Response to Comments: MolDX: Minimal Residual Disease Testing for Cancer (DL38835) (A58930) — cms.gov; accessed 2026-07-27.
6. C82.18 — Follicular lymphoma grade II, lymph nodes of multiple sites | ICD-10 Code · Eleplan — eleplan.com; accessed 2026-07-27.