C90.30
BillableSolitary plasmacytoma not having achieved remission
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C90.30 an HCC code?
Yes. C90.30 maps to Lymphoma and Other Cancers 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 C90.30
For C90.30 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 C90.30 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C90.30 is the ICD-10-CM diagnosis code for solitary plasmacytoma not having achieved remission. A single tumor made of plasma cells that has not responded to treatment or achieved remission. C90.30 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, C90.30 maps to Lymphoma and Other Cancers (HCC 19) with a community, non-dual, aged base RAF weight of 0.105. Under the older V24 model, C90.30 mapped to the same category but with a base RAF weight of 0.675 — V28 recalibrated weights across the entire model. 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.
Solitary plasmacytoma is a single lesion; if multiple lesions are present, consider multiple myeloma codes instead. Because C90.30 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 C90.30 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Solitary plasmacytoma is a single lesion; if multiple lesions are present, consider multiple myeloma codes instead
- •Document the treatment response status; 'not having achieved remission' means the patient has not reached remission status
Clinical Significance
Solitary plasmacytoma (of bone) is a single osseous lesion composed of neoplastic plasma cells without evidence of systemic multiple myeloma. It most commonly affects the axial skeleton, particularly the vertebrae. Without achieving remission, there is a significant risk of progression to multiple myeloma, which occurs in approximately 50-65% of cases within 10 years. The lesion may cause pathologic fractures and spinal cord compression.
Documentation Requirements
- ✓Documentation must include tissue biopsy confirming a monoclonal plasma cell tumor in bone.
- ✓Imaging confirming a single bone lesion with no additional skeletal involvement, bone marrow biopsy excluding myeloma, serum and urine protein electrophoresis, and treatment approach (typically radiation) must be documented.
- ✓Non-remission status and any structural complications must be recorded.