ICD-10 G93.42
Billable / Specific HCC v28: 52 CCMegalencephalic leukoencephalopathy with subcortical cysts
About ICD-10-CM G93.42
ICD-10-CM code G93.42 represents Megalencephalic leukoencephalopathy with subcortical cysts. This is a billable/specific code in the Nervous System chapter (block G93). The 2026 edition of ICD-10-CM G93.42 became effective on October 1, 2025.
Coding Tips for G93.42
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
G93.42 is a CMS-HCC v28 risk-adjustment code (category 52). 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.
G93.42 is designated CC for MS-DRG grouping. On inpatient claims, this code can shift the DRG to the with-CC variant when documented as a present-on-admission secondary diagnosis. Hospital CDI programs flag CC opportunities during chart review. Failure to capture this code may leave 30 to 80 percent of the inpatient stay revenue unrealized.
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, CC
codes Megalencephalic leukoencephalopathy with subcortical cysts. As a Complication/Comorbidity (CC), this contributes to DRG severity adjustment when documented alongside the principal diagnosis.
Medicare LCD Coverage for G93.42
Local Coverage Determinations (LCDs) from CMS MACs that list G93.42 as a covered diagnosis.
Showing top 10 of 40 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing G93.42.
1 Cigna
2 Medicare
CPT Codes Commonly Billed with G93.42
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.
Codes Adjacent To G93.42
Other codes in section G89-G99 (Other disorders of the nervous system).
ICD-10 G93.42, Billing FAQ
Is ICD-10 code G93.42 billable? +
Yes, G93.42 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
Does G93.42 affect Medicare Advantage HCC risk adjustment? +
Yes. G93.42 maps to CMS-HCC v28 category 52. Capture this diagnosis annually for accurate Medicare Advantage risk score.
Is G93.42 a CC or MCC for inpatient DRG? +
Yes, this code is designated as CC. Documenting as a secondary diagnosis on inpatient claims can shift the DRG to a higher-weighted category.
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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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