2027 ICD-10-CM Diagnosis Code G93.5Compression of brain
ICD-10-CM Codes›G00–G99›G89-G99›G93
- Billable — Valid for Submission
- MCC — Major Complication or Comorbidity
- Risk Adjusts — HCC 202
- Chronic Condition
G93.5 is a billable ICD-10-CM diagnosis code for compression of brain. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 80 through 81. As a secondary diagnosis, it counts as a major complication or comorbidity (MCC) and places an inpatient stay in the highest severity level of its MS-DRG family. It does not count, however, when the principal diagnosis is one of 3 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other nervous system disorders (neither hereditary nor degenerative).
For Medicare Advantage risk adjustment, G93.5 maps to CMS-HCC Category 202 (Coma, Brain Compression/Anoxic Damage) under the V28 model, adding a risk factor of about 0.543 for a community, non-dual, aged beneficiary in payment year 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
G93.5 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.
Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Brain stem compression
- Brain stem herniation
- Central transtentorial herniation
- Cerebellar hernia
- Cerebellar pressure cone
- Cerebral herniation
- Chiari malformation
- Chiari malformation type I
- Compression of brain
- Compression of brain due to focal lesion
- Compression of optic radiation
- Compression of visual cortex
- Craniosynostosis, facial dysmorphism, Chiari-1 malformation, developmental and language delay syndrome
- Disorder of optic radiation
- Herniation under falx cerebri
- Hindbrain hernia headache
- Non-traumatic hematoma of subdural space of neuraxis
- Nontraumatic intracranial subdural hematoma
- Nontraumatic intracranial subdural hematoma with brain compression
- Nontraumatic intracranial subdural hemorrhage
- Nontraumatic subarachnoid hemorrhage with brain compression
- Posterior fossa compression syndrome
- Spontaneous cerebral hemorrhage with compression of brain
- Tonsillar hernia into foramen magnum
- Transtentorial hernia
- Transtentorial herniation downwards
- Transtentorial herniation upwards
- Uncinate herniation
- Upwards herniation of cerebellum
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to G93.5: its own notes plus those printed at Chapter 6. A note printed at a category, block or chapter applies to every code under it.
Applicable To
Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.
- Arnold-Chiari type 1 compression of brain
- Compression of brain (stem)
- Herniation of brain (stem)
- Midline shift of brain
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
- traumatic compression of brain (S06.A-)
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
type I G93.5
brain (stem) G93.5
nontraumatic G93.5
Herniation See Also: Hernia;
brain (stem) G93.5
nontraumatic G93.5
cerebral G93.5
nontraumatic G93.5
Malformation (congenital) See Also: Anomaly;
brain G93.5
cone, tentorial G93.5
midline, brain G93.5
Syndrome See Also: Disease;
foramen magnum G93.5
fossa compression G93.5
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Cerebral Compression
the build up of pressure on the brain secondary to edema or bleeding which gradually leads to deterioration of level of consciousness.
Patient EducationClinical
Brain Diseases
Your brain is the control center of your body. It controls your thoughts, memory, speech, and movement. It regulates the function of many organs. It's part of your nervous system, which also includes your spinal cord and peripheral nerves. The nervous system sends signals between your brain and the rest of the body.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert G93.5 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About G93.5Overview
What is the ICD-10 code for compression of brain?
The ICD-10-CM code for compression of brain is G93.5 (sometimes written as G935). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is G93.5 (Other disorders of brain) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report compression of brain on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does G93.5 group to?
When compression of brain is the principal diagnosis on an inpatient stay, it groups to MS-DRG 81, 80, with relative weights from 0.7941 to 1.7476 depending on complications. Higher weights mean higher Medicare reimbursement.
Is G93.5 a CC or MCC?
CMS lists G93.5 as an MCC (major complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it places the inpatient stay in the highest-weighted DRG of its severity family. It does not count when the principal diagnosis is one of the 3 closely related codes in its exclusion list.
Can G93.5 be reported with a code from S06.A?
Not as a rule. The Excludes1 note on G93.5 lists "traumatic compression of brain (S06.A-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
What HCC is G93.5?
G93.5 (compression of brain) maps to CMS-HCC Category 202 (Coma, Brain Compression/Anoxic Damage), commonly written as HCC 202, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 80 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. It does not map to any RxHCC in the Part D prescription drug model.
Does G93.5 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, G93.5 adds a risk adjustment factor of about 0.543 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.097 to 0.721 depending on the payment segment). A more severe related category (HCC 63, HCC 397, and HCC 398) supersedes it when both are reported. See the full factor table on the HCC 202 category page.
