C81.16
BillableNodular sclerosis Hodgkin lymphoma, intrapelvic lymph nodes
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C81.16 an HCC code?
Yes. C81.16 maps to Breast, Prostate, Colorectal and Other Cancers and Tumors under the CMS-HCC V28 risk adjustment model (and Lymphoma and Other Cancers under V24).
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
MEAT Criteria for C81.16
For C81.16 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically — it has to be re-documented and supported each calendar year.
- MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
- EEvaluate: test results, medication response, or physical findings reviewed by the provider
- AAssess: explicit mention in the assessment or plan with acknowledgment of status
- TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed C81.16 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C81.16 is the ICD-10-CM diagnosis code for nodular sclerosis hodgkin lymphoma, intrapelvic lymph nodes. A type of Hodgkin lymphoma with nodular sclerosis pattern affecting lymph nodes inside the pelvis. C81.16 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering malignant neoplasms of lymphoid, hematopoietic and related tissue (c81-c96).
Under the CMS-HCC V28 risk adjustment model, C81.16 maps to Breast, Prostate, Colorectal and Other Cancers and Tumors (HCC 21) with a community, non-dual, aged base RAF weight of 0.545. Under the older CMS-HCC V24 model, C81.16 maps to Lymphoma and Other Cancers (HCC 10) with a community, non-dual, aged base RAF weight of 0.675. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.
Character '6' indicates intrapelvic lymph node sites; imaging studies should confirm pelvic involvement. Because C81.16 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for C81.16 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Character '6' indicates intrapelvic lymph node sites; imaging studies should confirm pelvic involvement
- •Seventh character extension is required for complete coding
Clinical Significance
Nodular sclerosis Hodgkin lymphoma of intrapelvic lymph nodes indicates deep pelvic lymph node involvement, which is an uncommon presentation for Hodgkin lymphoma. Intrapelvic disease is typically discovered on cross-sectional imaging rather than physical examination. This finding usually indicates Stage II or higher disease depending on additional sites of involvement and generally requires systemic chemotherapy.
Documentation Requirements
- ✓Pathology confirming nodular sclerosis subtype
- ✓Cross-sectional imaging documenting intrapelvic lymph node involvement
- ✓Specific pelvic lymph node groups identified (iliac, obturator, presacral)
- ✓Distinction from inguinal lymph nodes (C81.15) and intra-abdominal lymph nodes (C81.13)
- ✓Complete staging workup
- ✓Treatment plan
Commonly Confused Codes
- •C81.15 — Nodular sclerosis, inguinal/lower limb: Superficial groin nodes, not deep pelvic nodes
- •C81.13 — Nodular sclerosis, intra-abdominal: Abdominal lymph nodes are anatomically separate from pelvic nodes
- •C81.06 — NLPHL, intrapelvic: Different subtype at the same location
- •C81.10 — Nodular sclerosis, unspecified site: Use C81.16 when pelvic node involvement is documented