ICD-10 I38
Billable / Specific CCEndocarditis, valve unspecified
About ICD-10-CM I38
ICD-10-CM code I38 represents Endocarditis, valve unspecified. This is a billable/specific code in the Circulatory System chapter (block I38). The 2026 edition of ICD-10-CM I38 became effective on October 1, 2025.
Coding Tips for I38
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
I38 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 I38. The conditions are mutually exclusive (e.g., congenital vs acquired forms).
- congenital insufficiency of cardiac valve NOS (Q24.8)
- congenital stenosis of cardiac valve NOS (Q24.8)
- endocardial fibroelastosis (I42.4)
- endocarditis specified as rheumatic (I09.1)
Includes
- endocarditis (chronic) NOS
- valvular incompetence NOS
- valvular insufficiency NOS
- valvular regurgitation NOS
- valvular stenosis NOS
- valvulitis (chronic) NOS
Inpatient DRG Impact, CC
codes Endocarditis, valve unspecified. As a Complication/Comorbidity (CC), this contributes to DRG severity adjustment when documented alongside the principal diagnosis.
Medicare LCD Coverage for I38
Local Coverage Determinations (LCDs) from CMS MACs that list I38 as a covered diagnosis.
Showing top 10 of 339 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing I38.
1 Aetna
2 Cigna
5 Medicare
CPT Codes Commonly Billed with I38
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 I38 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 |
|---|---|---|
| I38 | 42490 | 10000 |
| I38 | 42499 | 10000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To I38
Other codes in section I30-I5A (Other forms of heart disease).
ICD-10 I38, Billing FAQ
Is ICD-10 code I38 billable? +
Yes, I38 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 I38? +
Type 1 Excludes (never code together with I38): congenital insufficiency of cardiac valve NOS (Q24.8); congenital stenosis of cardiac valve NOS (Q24.8); endocardial fibroelastosis (I42.4)
Is I38 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 ICD-9 codes does I38 map to? +
Per CMS GEMs, I38 maps to ICD-9 codes: 42490, 42499. 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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