D33.9 ICD-10-CM Code: Benign neoplasm of central nervous system, unspecified
D33.9 maps to CMS-HCC V28 23. A source-labeled RAF reference is available. Confirm the documented diagnosis and applicable coding requirements. MEAT criteria · RAF Calculator · HCC Buddy coding tools
HCC Buddy Code Card
Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.
FY 2026 Apr update / Neoplasms (C00-D49) / Benign neoplasms, except benign neuroendocrine tumors (D10-D36)
D33.9
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceBenign neoplasm of central nervous system, unspecified
A non-cancerous tumor of the brain or spinal cord when the specific location cannot be determined.
Buddy Insight
Benign neoplasm of the central nervous system, unspecified, represents a benign CNS tumor where the specific anatomical location cannot be determined from the medical record.
CMS-HCC V28
MappedHCC 23
Coefficient HCC 23: 0.186 (Community Non-Dual Aged (CNA))
CMS-HCC V24
HistoricalHistorical
Not used for CY2026 payment
ACA/HHS
MappedHCC 012
Code-level coefficient reference
ESRD/PACE
MappedHCC 12
Code-level coefficient reference
RXHCC
MappedHCC 22
Code-level coefficient reference
Code Book Path
Inclusion Terms
Official- Benign neoplasm of nervous system (central) NOS
Excludes 2
OfficialNo Excludes 2 notes are included in this display for D33.9. Check the code and parent instructions in the Code Book.
Related Codes
Includes
OfficialNo Includes notes are included in this display for D33.9. Check the code and parent instructions in the Code Book.
Excludes 1
Official- angioma (D18.0-)Inherited from D33
- benign neoplasm of meninges (D32.-)Inherited from D33
- benign neoplasm of peripheral nerves and autonomic nervous system (D36.1-)Inherited from D33
- hemangioma (D18.0-)Inherited from D33
- neurofibromatosis (Q85.0-)Inherited from D33
- retro-ocular benign neoplasm (D31.6-)Inherited from D33
Code First
OfficialNo Code First sequencing instructions are included in this display for D33.9. Check the code and parent instructions in the Code Book.
Use Additional
OfficialNo Use Additional Code instructions are included in this display for D33.9. Check the code and parent instructions in the Code Book.
Code Also
OfficialNo Code Also instructions are included in this display for D33.9. 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 D33.9 an HCC code?
Yes. D33.9 (Benign neoplasm of central nervous system, unspecified) maps to HCC 23, Prostate, Breast, and Other Cancers and Tumors under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 0.186. 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: D33.9 is billable and maps to V28 HCC 23, Prostate, Breast, and Other Cancers and Tumors. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.
- Code
- D33.9
- Description
- Benign neoplasm of central nervous system, unspecified
- HCC (V28)
- HCC 23 — Prostate, Breast, and Other Cancers and Tumors
- RAF reference coefficient
- 0.186
- 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 D33.9 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →
MEAT review for D33.9
For D33.9, 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
Get the V28 mapping + MEAT cheat sheet
One printable reference: check representative V28 mappings and the documentation reminders your note needs. Free, no card.
Free PDF. No card. Unsubscribe anytime.
What This Code Means
D33.9 is the ICD-10-CM diagnosis code for benign neoplasm of central nervous system, unspecified. A non-cancerous tumor of the brain or spinal cord when the specific location cannot be determined. D33.9 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering benign neoplasms, except benign neuroendocrine tumors (d10-d36).
Under the CMS-HCC V28 risk adjustment model, D33.9 maps to Prostate, Breast, and Other Cancers and Tumors (HCC 23) with a source-labeled community, non-dual, aged reference coefficient of 0.186. 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.
This is an unspecified code; query the provider for more specific anatomical location when possible. For D33.9, 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 D33.9 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This is an unspecified code; query the provider for more specific anatomical location when possible
- •Use only when documentation does not provide enough detail to assign a more specific code
Clinical Significance
Benign neoplasm of the central nervous system, unspecified, represents a benign CNS tumor where the specific anatomical location cannot be determined from the medical record. This code should be rarely necessary given the availability of modern neuroimaging that typically localizes tumors precisely. It may be appropriate as a temporary code pending definitive imaging evaluation.
Documentation Requirements
- ✓Documentation of a benign CNS neoplasm from any source is the minimum requirement.
- ✓All available imaging (MRI brain and/or spine) should be reviewed to determine the specific location.
- ✓Query the provider for clarification if imaging has been performed.
- ✓Document the reason the location remains unspecified.
Commonly Confused Codes
- •D33.0-D33.7 are site-specific codes preferred when location is known
- •D32.0-D32.9 (meningeal tumors) are for meningeal locations
- •D43.9 (CNS uncertain behavior, unspecified) is for when the benign vs. malignant nature is also unclear
- •D33.2 (brain, unspecified) is slightly more specific if the brain is known to be involved.