ICD-10 G93.5
Billable / Specific HCC v28: 80 MCCCompression of brain
About ICD-10-CM G93.5
ICD-10-CM code G93.5 represents Compression of brain. This is a billable/specific code in the Nervous System chapter (block G93). The 2026 edition of ICD-10-CM G93.5 became effective on October 1, 2025.
Coding Tips for G93.5
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
G93.5 is a CMS-HCC v28 risk-adjustment code (category 80). To count for the patient Risk Adjustment Factor (RAF), document the diagnosis with MEAT language each calendar year: Monitored, Evaluated, Assessed, Treated. A diagnosis on the problem list alone does not satisfy CMS RADV audit standards. Include the diagnosis in the assessment with current status and current treatment plan.
G93.5 is designated MCC for MS-DRG grouping. On inpatient claims, this code can shift the DRG to the with-MCC variant when documented as a present-on-admission secondary diagnosis. Hospital CDI programs flag MCC opportunities during chart review. Failure to capture this code may leave 30 to 80 percent of the inpatient stay revenue unrealized.
Inclusion Terms / Approximate Synonyms
Clinical terms and conditions classified under G93.5. Per CMS ICD-10-CM Tabular 2026.
- Arnold-Chiari type 1 compression of brain
- Compression of brain (stem)
- Herniation of brain (stem)
Type 1 Excludes
Pure excludes, these codes can never be coded together with G93.5. The conditions are mutually exclusive (e.g., congenital vs acquired forms).
- traumatic compression of brain (S06.A-)
Medicare Advantage HCC Impact
Capture this diagnosis annually for accurate risk adjustment. Missed HCC captures are the #1 revenue leak in Medicare Advantage risk programs.
Inpatient DRG Impact, MCC
codes Compression of brain. As a Major Complication/Comorbidity (MCC), this can shift the DRG assignment to a higher-weighted category, substantial reimbursement impact.
Medicare LCD Coverage for G93.5
Local Coverage Determinations (LCDs) from CMS MACs that list G93.5 as a covered diagnosis.
Showing top 10 of 70 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing G93.5.
2 Cigna
5 Medicare
1 Aetna
CPT Codes Commonly Billed with G93.5
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
We don't have CPT pairings indexed for this specific code yet. Use the CPT search above to find common procedures, or check your payer's published medical policy for code-specific guidance.
Convert G93.5 to ICD-9-CM
Per CMS General Equivalence Mappings (GEMs), useful for legacy data review and historical claim analysis.
| ICD-10 | ICD-9 | Mapping Flags |
|---|---|---|
| G93.5 | 3484 | 00000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To G93.5
Other codes in section G89-G99 (Other disorders of the nervous system).
ICD-10 G93.5, Billing FAQ
Is ICD-10 code G93.5 billable? +
Yes, G93.5 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
What other names or terms map to G93.5? +
ICD-10 G93.5 includes: Arnold-Chiari type 1 compression of brain; Compression of brain (stem); Herniation of brain (stem).
What codes are Type 1 Excludes for G93.5? +
Type 1 Excludes (never code together with G93.5): traumatic compression of brain (S06.A-)
Does G93.5 affect Medicare Advantage HCC risk adjustment? +
Yes. G93.5 maps to CMS-HCC v28 category 80. Capture this diagnosis annually for accurate Medicare Advantage risk score.
Is G93.5 a CC or MCC for inpatient DRG? +
Yes, this code is designated as MCC. Documenting as a secondary diagnosis on inpatient claims can shift the DRG to a higher-weighted category.
What ICD-9 codes does G93.5 map to? +
Per CMS GEMs, G93.5 maps to ICD-9 codes: 3484. Useful for legacy data review and historical claim analysis.
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Reviewed by the PayerReady Medical Coding Team
Verified against the CMS 2026 code set on May 31, 2026.
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