ICD-10 I77.74
Billable / Specific HCC v28: 107 MCCDissection of vertebral artery
About ICD-10-CM I77.74
ICD-10-CM code I77.74 represents Dissection of vertebral artery. This is a billable/specific code in the Circulatory System chapter (block I77). The 2026 edition of ICD-10-CM I77.74 became effective on October 1, 2025.
Coding Tips for I77.74
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
I77.74 is a CMS-HCC v28 risk-adjustment code (category 107). 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.
I77.74 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.
Type 2 Excludes
Not included here, the excluded code is not part of I77.74, but a patient may have both conditions at the same time. Both codes may be coded together when applicable.
- aneurysm of vertebral artery (I72.6)
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 Dissection of vertebral artery. As a Major Complication/Comorbidity (MCC), this can shift the DRG assignment to a higher-weighted category, substantial reimbursement impact.
Medicare LCD Coverage for I77.74
Local Coverage Determinations (LCDs) from CMS MACs that list I77.74 as a covered diagnosis.
Showing top 10 of 326 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing I77.74.
1 Cigna
5 Medicare
1 Aetna
CPT Codes Commonly Billed with I77.74
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 I77.74 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 |
|---|---|---|
| I77.74 | 44324 | 00000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To I77.74
Other codes in section I70-I79 (Diseases of arteries, arterioles and capillaries).
ICD-10 I77.74, Billing FAQ
Is ICD-10 code I77.74 billable? +
Yes, I77.74 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
What codes are Type 2 Excludes for I77.74? +
Type 2 Excludes (may be coded together when both conditions exist): aneurysm of vertebral artery (I72.6)
Does I77.74 affect Medicare Advantage HCC risk adjustment? +
Yes. I77.74 maps to CMS-HCC v28 category 107. Capture this diagnosis annually for accurate Medicare Advantage risk score.
Is I77.74 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 I77.74 map to? +
Per CMS GEMs, I77.74 maps to ICD-9 codes: 44324. 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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