2026 ICD-10-CM Diagnosis Code D33.9Benign neoplasm of central nervous system, unspecified
ICD-10-CM Codes›C00–D49›D10-D36›D33
- Billable — Valid for Submission
- Not Chronic
D33.9 is a billable ICD-10-CM diagnosis code for benign neoplasm of central nervous system, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). Coders also document this condition as benign ependymoma of central nervous system. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Benign neoplasms.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Benign ependymoma of central nervous system
- Benign neoplasm of central nervous system
- Benign neoplasm of nervous system
- Extraneural perineurioma
- Gangliocytoma of central nervous system
- Intraneural perineurioma
- Neoplasm of spinal nerve and sheath
- Perineurioma
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Benign neoplasm of nervous system (central) NOS
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Table of NeoplasmsClinical
Anatomical sites in the Table of Neoplasms that reference this code family.
Patient EducationClinical
Benign Tumors
Tumors are abnormal growths in your body. They can be either benign or malignant. Benign tumors aren't cancer. Malignant ones are. Benign tumors grow only in one place. They cannot spread or invade other parts of your body. Even so, they can be dangerous if they press on vital organs, such as your brain.
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Convert D33.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About D33.9Overview
Is D33.9 a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report benign neoplasm of central nervous system, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What is the ICD-9 equivalent of D33.9?
Under the General Equivalence Mappings, benign neoplasm of central nervous system, unspecified converts to ICD-9-CM 225.9 (benign neo nerv sys NOS). The mapping is approximate, so confirm the match fits the documentation.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
