ICD-10 G40.C09
Billable / Specific HCC v28: 79 CCLafora progressive myoclonus epilepsy, not intractable, without status epilepticus
About ICD-10-CM G40.C09
ICD-10-CM code G40.C09 represents Lafora progressive myoclonus epilepsy, not intractable, without status epilepticus. This is a billable/specific code in the Nervous System chapter (block G40). The 2026 edition of ICD-10-CM G40.C09 became effective on October 1, 2025.
Coding Tips for G40.C09
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
G40.C09 is a CMS-HCC v28 risk-adjustment code (category 79). 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.
G40.C09 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.
Inclusion Terms / Approximate Synonyms
Clinical terms and conditions classified under G40.C09. Per CMS ICD-10-CM Tabular 2026.
- Lafora progressive myoclonus epilepsy NOS
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 Lafora progressive myoclonus epilepsy, not intractable, without status epilepticus. As a Complication/Comorbidity (CC), this contributes to DRG severity adjustment when documented alongside the principal diagnosis.
Medicare LCD Coverage for G40.C09
Local Coverage Determinations (LCDs) from CMS MACs that list G40.C09 as a covered diagnosis.
Showing top 10 of 28 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing G40.C09.
1 Medicare
CPT Codes Commonly Billed with G40.C09
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 G40.C09
Other codes in section G40-G47 (Episodic and paroxysmal disorders).
ICD-10 G40.C09, Billing FAQ
Is ICD-10 code G40.C09 billable? +
Yes, G40.C09 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 G40.C09? +
ICD-10 G40.C09 includes: Lafora progressive myoclonus epilepsy NOS.
Does G40.C09 affect Medicare Advantage HCC risk adjustment? +
Yes. G40.C09 maps to CMS-HCC v28 category 79. Capture this diagnosis annually for accurate Medicare Advantage risk score.
Is G40.C09 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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