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D33.1 ICD-10-CM Code: Benign neoplasm of brain, infratentorial

Compare with another codeCheck this code on a claim

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

Billable · FY2027A valid, specific ICD-10-CM code, reportable for dates of service in FY2027.

What you need to know

Source: CMS/NCHS Official ICD-10-CM tabular notes, quoted. From the CMS/NCHS tabular list for the release in force. A note the category or block publishes applies to this code too; the Instructions section marks which is which.

Excludes1Never report with this code
  • angioma (D18.0-)
  • benign neoplasm of meninges (D32.-)
  • benign neoplasm of peripheral nerves and autonomic nervous system (D36.1-)
  • hemangioma (D18.0-)

+2 more in Instructions

IncludesWhat this code covers
  • Benign neoplasm of brain stem
  • Benign neoplasm of cerebellum
  • Benign neoplasm of fourth ventricle

Most relevant related codes MedCoder-derived

Read off the official notes above and this code’s own position in the tabular list. Which to report is a documentation question; Compare shows the two side by side.

CompareCheck ClaimView Related Codes

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v44, Appendix B.

  • MS-DRG 054 — NERVOUS SYSTEM NEOPLASMS WITH MCC (MDC 01)
  • MS-DRG 055 — NERVOUS SYSTEM NEOPLASMS WITHOUT MCC (MDC 01)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Risk Adjustment (CMS-HCC)

Payment categories this diagnosis maps to under CMS-HCC V28, payment year 2026.

  • HCC 23 — Prostate, Breast, and Other Cancers and Tumors

Other models: CMS-HCC V22 HCC 12 · RxHCC V08 HCC 22

Risk scores depend on the enrollee's full accepted diagnosis set and segment; a category mapping alone does not determine payment.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for D33.1 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2027Effective: October 1, 2026

Trace:FY2027 changesChange historyRelease, file and checksum

Notes without a marker are published on D33.1 itself; “inherited from” names the category or block whose note applies here.

Inclusion Terms

Alternative terms the tabular list files under this code.

  • Benign neoplasm of brain stem
  • Benign neoplasm of cerebellum
  • Benign neoplasm of fourth ventricle

Excludes1 — Not Coded Here

Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Source: inherited from D33

Coder workflow for D33.1

MedCoder structured workflow — derived from this code’s own official record

Before you code D33.1

  1. Confirm the documented site and behavior (this code’s block classifies benign neoplasms), whether the site is primary or secondary, and whether the malignancy is current or a personal history: a previously excised malignancy with no further treatment and no evidence of disease is history, not current disease. Verify the site against the Table of Neoplasms. Neoplasm chapter guidelines (Guidelines I.C.2.a, I.C.2.d, I.C.2.m).

    See the Table of Neoplasms entries · Guide: Active cancer vs history of cancer →

  2. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with D33.1. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

    See the official tabular notes

Choose the right path

  1. Does the documentation support a condition named in D33.1’s Excludes1 note?
    Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
    No → Continue.

    ReviewD18.0, D32, D36.1, Q85.0, D31.6

Consider D33.1. Then confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement
Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
Anatomical site
At the most specific level the record states; a site the classification separates cannot be assumed from a procedure or a measurement.
Behavior and current-versus-history status
Malignant, in situ, benign or uncertain; primary or secondary; current disease or personal history (Guidelines I.C.2.m).

Official instructions as workflow

  • Excludes1 — check before selecting D33.1(6 notes)

    Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with D33.1: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

    CompareD18.0, D32, D36.1, Q85.0, D31.6

    See the official tabular notes · Guidelines I.A.12.a

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Documentation: Both the condition D33.1 describes and a condition named in its Excludes1 note are documented for the same encounter.

Coding question: Can both codes be reported?

Path: Review the Excludes1 note and the excluded code, and look for a provider statement on whether the two conditions are related.

Reason: Excludes1 means the two are not coded together; the exception is when the record shows the conditions are unrelated to each other (Guidelines I.A.12.a).

ReviewD18.0, D32, D36.1, Q85.0, D31.6

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Coding context

Guidelines, coding notes, decision aids, relationships (with MS-DRG and CCSR classification), hierarchy, HCC, coverage and the context map: what a coder reaches for after the core. Each section names whether it is official source data, a MedCoder-derived relationship or MedCoder editorial.

Code Overview

Benign neoplasm of brain, infratentorial is a billable ICD-10-CM diagnosis code (D33.1).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Verify Before Coding

  • No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder-derived relationships — computed from published CMS and AHRQ datasets

Other codes that name D33.1 or its code family, from the CMS ICD-10-CM tabular instructional notes, the CMS Table of Neoplasms and the CMS Table of Neoplasms (site match derived from the code title). Tabular-note edges are stored at the code family level that carries each note.

Referenced by 1 Excludes1 note: D33.0 — Benign neoplasm of brain, supratentorial.

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

Referenced by 5 Same-site neoplasm codes: C71.6 — Malignant neoplasm of cerebellumCompare D33.1 vs C71.6 →, C71.7 — Malignant neoplasm of brain stemCompare D33.1 vs C71.7 →, C79.31 — Secondary malignant neoplasm of brainCompare D33.1 vs C79.31 →, D43.1 — Neoplasm of uncertain behavior of brain, infratentorialCompare D33.1 vs D43.1 →, D49.6 — Neoplasm of unspecified behavior of brainCompare D33.1 vs D49.6 →.

These codes represent related neoplasm behaviors affecting the same anatomic site.

Referenced by 1 Screening & history code: Z85.841 — Personal history of malignant neoplasm of brainCompare D33.1 vs Z85.841 →.

These codes represent screening tests and history codes that refer to this active disease condition.

MS-DRG Grouper Relationships (FY2027)

Potential MS-DRG participation — not a DRG assignment.

FY2027 MS-DRG: not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity for that release.

Named in the grouper logic of 2 MS-DRGs: DRG 054 (MDC 01), DRG 055 (MDC 01).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):NEO073 — Benign neoplasms (default).

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same CMS-HCC risk category (V28)

CMS maps these diagnoses to the same Hierarchical Condition Category (Prostate, Breast, and Other Cancers and Tumors) for risk-adjusted payment.

D03.70 — Melanoma in situ of unspecified lower limb, including hip, D03.71 — Melanoma in situ of right lower limb, including hip, D03.72 — Melanoma in situ of left lower limb, including hip, D03.8 — Melanoma in situ of other sites, D03.9 — Melanoma in situ, unspecified, D18.02 — Hemangioma of intracranial structures, D32.0 — Benign neoplasm of cerebral meninges, D32.1 — Benign neoplasm of spinal meninges, D32.9 — Benign neoplasm of meninges, unspecified, D33.0 — Benign neoplasm of brain, supratentorial, D33.2 — Benign neoplasm of brain, unspecified, D33.3 — Benign neoplasm of cranial nerves, D33.4 — Benign neoplasm of spinal cord, D33.7 — Benign neoplasm of other specified parts of central nervous system, D33.9 — Benign neoplasm of central nervous system, unspecified, D35.2 — Benign neoplasm of pituitary gland, D35.3 — Benign neoplasm of craniopharyngeal duct, D35.4 — Benign neoplasm of pineal gland, D42.0 — Neoplasm of uncertain behavior of cerebral meninges, D42.1 — Neoplasm of uncertain behavior of spinal meninges, +213 more

Related risk categories

These categories interact through CMS's HCC hierarchy — one can suppress the other's risk-adjustment weight when both are present on a claim.

Cancer Metastatic to Lung, Liver, Brain, and Other Organs; Acute Myeloid Leukemia Except Promyelocytic, Cancer Metastatic to Bone, Other and Unspecified Metastatic Cancer; Acute Leukemia Except Myeloid, Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers, Lung and Other Severe Cancers, Lymphoma and Other Cancers, Bladder, Colorectal, and Other Cancers

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Benign neoplasms).

D31.60 — Benign neoplasm of unspecified site of unspecified orbit, D31.61 — Benign neoplasm of unspecified site of right orbit, D31.62 — Benign neoplasm of unspecified site of left orbit, D31.90 — Benign neoplasm of unspecified part of unspecified eye, D31.91 — Benign neoplasm of unspecified part of right eye, D31.92 — Benign neoplasm of unspecified part of left eye, D32.0 — Benign neoplasm of cerebral meninges, D32.1 — Benign neoplasm of spinal meninges, D32.9 — Benign neoplasm of meninges, unspecified, D33.0 — Benign neoplasm of brain, supratentorial, D33.2 — Benign neoplasm of brain, unspecified, D33.3 — Benign neoplasm of cranial nerves, D33.4 — Benign neoplasm of spinal cord, D33.7 — Benign neoplasm of other specified parts of central nervous system, D33.9 — Benign neoplasm of central nervous system, unspecified, D34 — Benign neoplasm of thyroid gland, D35.00 — Benign neoplasm of unspecified adrenal gland, D35.01 — Benign neoplasm of right adrenal gland, D35.02 — Benign neoplasm of left adrenal gland, D35.1 — Benign neoplasm of parathyroid gland, +252 more

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main term “Papilloma”; these codes share that main term but sit in a different category of the Tabular List.

A63.0 — Anogenital (venereal) warts (acuminatum), A66.1 — Multiple papillomata and wet crab yaws (yaws, plantar or palmar), A67.0 — Primary lesions of pinta (benign pinta), C71.5 — Malignant neoplasm of cerebral ventricle (choroid plexus, malignant), D14.0 — Benign neoplasm of middle ear, nasal cavity and accessory sinuses (Schneiderian, unspecified site), D27.9 — Benign neoplasm of unspecified ovary (serous surface, unspecified site), D30.1 — Benign neoplasm of renal pelvis (renal pelvis, benign), D30.2 — Benign neoplasm of ureter (ureter, benign), D39.10 — Neoplasm of uncertain behavior of unspecified ovary (serous surface, borderline malignancy, unspecified site), D41.1 — Neoplasm of uncertain behavior of renal pelvis (renal pelvis), D41.2 — Neoplasm of uncertain behavior of ureter (ureter), D41.4 — Neoplasm of uncertain behavior of bladder (bladder), L82.0 — Inflamed seborrheic keratosis (basal cell, inflamed), L82.1 — Other seborrheic keratosis (basal cell)

Lab tests where this diagnosis supports Medicare coverage (NCD)

Medicare's National Coverage Determination (NCD) program lists this diagnosis as medical justification for these lab tests.

Iron Panel

Contextual Map

Every relationship of D33.1 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run D33.1 with this related code in Claim Check

Hierarchy

Same site

Referenced by Excludes1 notes

Referenced by Same-site neoplasm codes

Referenced by Screening & history codes MedCoder-derived

Clinical classification (CCSR)

Risk adjustment (CMS-HCC)

  • HCC 23 — Prostate, Breast, and Other Cancers and Tumors [CMS-HCC]— CMS-HCC V28 · 2026

MS-DRG Grouper

MDC crossing

  • MDC 01 — Diseases and Disorders of the Nervous System[MDC crossing]: “Diseases and Disorders of the Nervous System — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 8,919 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2027

Neoplasm sites (25)

  • Neoplasm, neoplastic, basis pedunculi — Neoplasm, neoplastic, basis pedunculi — Benign [Neoplasm table]: “Neoplasm, neoplastic, basis pedunculi (Benign)”— CMS Table of Neoplasms · icd10cm-fy2027
  • Neoplasm, neoplastic, brain NEC, cerebellopontine angle — Neoplasm, neoplastic, brain NEC, cerebellopontine angle — Benign [Neoplasm table]: “Neoplasm, neoplastic, brain NEC, cerebellopontine angle (Benign)”— CMS Table of Neoplasms · icd10cm-fy2027
  • Neoplasm, neoplastic, brain NEC, cerebellum NOS — Neoplasm, neoplastic, brain NEC, cerebellum NOS — Benign [Neoplasm table]: “Neoplasm, neoplastic, brain NEC, cerebellum NOS (Benign)”— CMS Table of Neoplasms · icd10cm-fy2027
  • Neoplasm, neoplastic, brain NEC, choroid plexus — Neoplasm, neoplastic, brain NEC, choroid plexus — Benign [Neoplasm table]: “Neoplasm, neoplastic, brain NEC, choroid plexus (Benign)”— CMS Table of Neoplasms · icd10cm-fy2027
  • Neoplasm, neoplastic, brain NEC, medulla oblongata — Neoplasm, neoplastic, brain NEC, medulla oblongata — Benign [Neoplasm table]: “Neoplasm, neoplastic, brain NEC, medulla oblongata (Benign)”— CMS Table of Neoplasms · icd10cm-fy2027
  • Neoplasm, neoplastic, brain NEC, midbrain — Neoplasm, neoplastic, brain NEC, midbrain — Benign [Neoplasm table]: “Neoplasm, neoplastic, brain NEC, midbrain (Benign)”— CMS Table of Neoplasms · icd10cm-fy2027
  • Neoplasm, neoplastic, brain NEC, peduncle — Neoplasm, neoplastic, brain NEC, peduncle — Benign [Neoplasm table]: “Neoplasm, neoplastic, brain NEC, peduncle (Benign)”— CMS Table of Neoplasms · icd10cm-fy2027
  • Neoplasm, neoplastic, brain NEC, pons — Neoplasm, neoplastic, brain NEC, pons — Benign [Neoplasm table]: “Neoplasm, neoplastic, brain NEC, pons (Benign)”— CMS Table of Neoplasms · icd10cm-fy2027
  • and 17 more

Index entries

  • Papilloma, choroid plexus (lateral ventricle) (third ventricle), fourth ventricle[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027

Nearest codes

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Reference

Index terms and tables, published questions and FAQ, every source behind this page with its release and checksum, the date-of-service check and the complete change history.

Indexed Clinical Terms (1)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

Neoplasm Table Sites (25)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Anatomical sites from the official ICD-10-CM Table of Neoplasms that map to this code, with the matching behavior column.

  • Neoplasm, neoplastic, basis pedunculi — Benign
  • Neoplasm, neoplastic, brain NEC, cerebellopontine angle — Benign
  • Neoplasm, neoplastic, brain NEC, cerebellum NOS — Benign
  • Neoplasm, neoplastic, brain NEC, choroid plexus — Benign
  • Neoplasm, neoplastic, brain NEC, medulla oblongata — Benign
  • Neoplasm, neoplastic, brain NEC, midbrain — Benign
  • Neoplasm, neoplastic, brain NEC, peduncle — Benign
  • Neoplasm, neoplastic, brain NEC, pons — Benign
  • Neoplasm, neoplastic, brain NEC, stem — Benign
  • Neoplasm, neoplastic, brain NEC, ventricle (floor), fourth — Benign
  • Neoplasm, neoplastic, cerebellopontine (angle) — Benign
  • Neoplasm, neoplastic, cerebellum, cerebellar — Benign
  • Neoplasm, neoplastic, cerebrum, cerebral (cortex) (hemisphere) (white matter), peduncle — Benign
  • Neoplasm, neoplastic, cerebrum, cerebral (cortex) (hemisphere) (white matter), ventricle, fourth — Benign
  • Neoplasm, neoplastic, ependyma (brain), fourth ventricle — Benign
  • Neoplasm, neoplastic, medulla, oblongata — Benign
  • Neoplasm, neoplastic, midbrain — Benign
  • Neoplasm, neoplastic, olive (brain) — Benign
  • Neoplasm, neoplastic, peduncle, cerebral — Benign
  • Neoplasm, neoplastic, pons (varolii) — Benign
  • Neoplasm, neoplastic, pyramid (brain) — Benign
  • Neoplasm, neoplastic, spine, spinal (column), bulb — Benign
  • Neoplasm, neoplastic, stem, brain — Benign
  • Neoplasm, neoplastic, ventricle (cerebral) (floor) (lateral) (third), fourth — Benign
  • Neoplasm, neoplastic, vermis, cerebellum — Benign

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2027 tabular list, index and tables, effective October 1, 2026 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v44.0 (October 2026) Release, file and checksum · Publisher’s page
Inpatient payment groups Official source data
CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v44 Release, file and checksum · Publisher’s page
Risk adjustment Official source data
2026 Mid-Year Final ICD-10 Mappings + Model Software (cms.gov/files/zip/2026-midyear-final-icd-10-mappings.zip, 2026-midyear-final-model-software.zip) — CMS-HCC V28, PY2026 mid-year final release Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder-derived relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder editorial explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Current data releases:ICD-10-CM FY2027 · ICD-10-PCS FY2027 · HCPCS October 2026 · MS-DRG v44 · Medicare Code Editor v44.0 · NCCI PTP Q4 2026 · MUE Q4 2026 · NCD code lists 2026-01 · LCD export September 28, 2026 · All releases and sources

Labels on this page: Official source data · MedCoder-derived relationship · MedCoder editorial explanation. How to read the labels · All data sources and release dates · CMS coding rules

Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "D33.1 — Benign neoplasm of brain, infratentorial." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/d33.1-benign-neoplasm-of-brain-infratentorial

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Benign neoplasm of brain, infratentorial

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027, and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to D33.1 in its code family, with their registry titles.

View all codes in the D33 family