ICD-10 G40.89
Billable / Specific HCC v28: 79 CCOther seizures
About ICD-10-CM G40.89
ICD-10-CM code G40.89 represents Other seizures. This is a billable/specific code in the Nervous System chapter (block G40). The 2026 edition of ICD-10-CM G40.89 became effective on October 1, 2025.
Coding Tips for G40.89
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
G40.89 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.
G40.89 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.
Type 1 Excludes
Pure excludes, these codes can never be coded together with G40.89. The conditions are mutually exclusive (e.g., congenital vs acquired forms).
- post traumatic seizures (R56.1)
- recurrent seizures NOS (G40.909)
- seizure NOS (R56.9)
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 Other seizures. As a Complication/Comorbidity (CC), this contributes to DRG severity adjustment when documented alongside the principal diagnosis.
Medicare LCD Coverage for G40.89
Local Coverage Determinations (LCDs) from CMS MACs that list G40.89 as a covered diagnosis.
Showing top 10 of 331 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing G40.89.
3 Cigna
5 Medicare
1 Aetna
CPT Codes Commonly Billed with G40.89
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
- 95711 CMS LCD: Billing and Coding: EEG � Ambulatory Monitoring CMS LCD
- 95714 CMS LCD: Billing and Coding: EEG � Ambulatory Monitoring CMS LCD
- 95726 CMS LCD: Billing and Coding: EEG � Ambulatory Monitoring CMS LCD
- 95709 CMS LCD: Billing and Coding: EEG � Ambulatory Monitoring CMS LCD
- 95723 CMS LCD: Billing and Coding: EEG � Ambulatory Monitoring CMS LCD
- 95710 CMS LCD: Billing and Coding: EEG � Ambulatory Monitoring CMS LCD
- 95716 CMS LCD: Billing and Coding: EEG � Ambulatory Monitoring CMS LCD
- 95707 CMS LCD: Billing and Coding: EEG � Ambulatory Monitoring CMS LCD
- 95712 CMS LCD: Billing and Coding: EEG � Ambulatory Monitoring CMS LCD
- 95724 CMS LCD: Billing and Coding: EEG � Ambulatory Monitoring CMS LCD
Convert G40.89 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 |
|---|---|---|
| G40.89 | 34580 | 10000 |
| G40.89 | 34581 | 10000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To G40.89
Other codes in section G40-G47 (Episodic and paroxysmal disorders).
ICD-10 G40.89, Billing FAQ
Is ICD-10 code G40.89 billable? +
Yes, G40.89 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
What codes are Type 1 Excludes for G40.89? +
Type 1 Excludes (never code together with G40.89): post traumatic seizures (R56.1); recurrent seizures NOS (G40.909); seizure NOS (R56.9)
Does G40.89 affect Medicare Advantage HCC risk adjustment? +
Yes. G40.89 maps to CMS-HCC v28 category 79. Capture this diagnosis annually for accurate Medicare Advantage risk score.
Is G40.89 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.
What CPT codes are commonly billed with G40.89? +
Procedures frequently paired with G40.89 include: 95711, 95714, 95726, 95709, 95723.
What ICD-9 codes does G40.89 map to? +
Per CMS GEMs, G40.89 maps to ICD-9 codes: 34580, 34581. 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 July 16, 2026.
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