C90.22 ICD-10-CM Code: Extramedullary plasmacytoma in relapse
C90.22 maps to CMS-HCC V28 19. A source-labeled RAF reference is available. Confirm the documented diagnosis and applicable coding requirements. MEAT criteria · RAF Calculator · HCC Buddy coding tools
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FY 2026 Apr update / Neoplasms (C00-D49) / Malignant neoplasms of lymphoid, hematopoietic and related tissue (C81-C96)
C90.22
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceExtramedullary plasmacytoma in relapse
A rare cancer of plasma cells located outside the bone marrow that has returned after a period of remission.
Buddy Insight
Extramedullary plasmacytoma in relapse indicates recurrence of the plasma cell tumor after achieving remission.
CMS-HCC V28
MappedHCC 19
Coefficient HCC 19: 1.798 (Community Non-Dual Aged (CNA))
CMS-HCC V24
HistoricalHistorical
Not used for CY2026 payment
ACA/HHS
MappedHCC 009
Code-level coefficient reference
ESRD/PACE
MappedHCC 9
Code-level coefficient reference
RXHCC
MappedHCC 16
Code-level coefficient reference
Code Book Path
Inclusion Terms
OfficialNo inclusion terms are included in this display for C90.22. Check the code and parent instructions in the Code Book.
Excludes 2
Official- Kaposi's sarcoma of lymph nodes (C46.3)Inherited from C81-C96
- secondary and unspecified neoplasm of lymph nodes (C77.-)Inherited from C81-C96
- secondary neoplasm of bone marrow (C79.52)Inherited from C81-C96
- secondary neoplasm of spleen (C78.89)Inherited from C81-C96
Related Codes
Includes
OfficialNo Includes notes are included in this display for C90.22. Check the code and parent instructions in the Code Book.
Excludes 1
Official- personal history of other malignant neoplasms of lymphoid, hematopoietic and related tissues (Z85.79)Inherited from C90
Code First
OfficialNo Code First sequencing instructions are included in this display for C90.22. Check the code and parent instructions in the Code Book.
Use Additional
OfficialNo Use Additional Code instructions are included in this display for C90.22. Check the code and parent instructions in the Code Book.
Code Also
OfficialNo Code Also instructions are included in this display for C90.22. Check the code and parent instructions in the Code Book.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →
Is C90.22 an HCC code?
Yes. C90.22 (Extramedullary plasmacytoma in relapse) maps to HCC 19, Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 1.798. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes. It is billable for payment year 2026.
Coder answer: C90.22 is billable and maps to V28 HCC 19, Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.
- Code
- C90.22
- Description
- Extramedullary plasmacytoma in relapse
- HCC (V28)
- HCC 19 — Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers
- RAF reference coefficient
- 1.798
- Billable
- Yes
- Payment year
- 2026
HCC Category Mapping
These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. Weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.
Work C90.22 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →
MEAT review for C90.22
For C90.22, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.
- 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
Coder workflow notes
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What This Code Means
C90.22 is the ICD-10-CM diagnosis code for extramedullary plasmacytoma in relapse. A rare cancer of plasma cells located outside the bone marrow that has returned after a period of remission. C90.22 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, C90.22 maps to Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers (HCC 19) with a source-labeled community, non-dual, aged reference coefficient of 1.798. For CY2026 non-PACE Medicare Advantage, CMS uses 100% of the 2024 CMS-HCC model (V28). PACE uses a separate model blend. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes.
Relapse indicates the cancer has recurred after previous remission; ensure documentation clearly states relapse or recurrence. For C90.22, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule. 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, source-labeled coefficient references, and MEAT documentation criteria for C90.22 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Relapse indicates the cancer has recurred after previous remission; ensure documentation clearly states relapse or recurrence
- •Do not confuse relapse with initial diagnosis or progression during active treatment
Clinical Significance
Extramedullary plasmacytoma in relapse indicates recurrence of the plasma cell tumor after achieving remission. Relapse may occur at the original site or at new extramedullary locations. Recurrence also raises concern for progression to systemic multiple myeloma, which requires comprehensive restaging workup. Treatment of relapsed disease may require different modalities than the initial approach.
Documentation Requirements
- ✓Documentation must demonstrate recurrence of the plasmacytoma after a documented period of remission, confirmed by imaging and biopsy.
- ✓Restaging workup including bone marrow biopsy and protein studies to exclude myeloma transformation, relapse location, new treatment plan, and disease extent must be recorded.