ICD-10 A77.40
Billable / Specific CCEhrlichiosis, unspecified
About ICD-10-CM A77.40
ICD-10-CM code A77.40 represents Ehrlichiosis, unspecified. This is a billable/specific code in the Infectious and Parasitic Diseases chapter (block A77). The 2026 edition of ICD-10-CM A77.40 became effective on October 1, 2025.
Coding Tips for A77.40
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
A77.40 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.
Inpatient DRG Impact, CC
codes Ehrlichiosis, unspecified. As a Complication/Comorbidity (CC), this contributes to DRG severity adjustment when documented alongside the principal diagnosis.
Medicare LCD Coverage for A77.40
Local Coverage Determinations (LCDs) from CMS MACs that list A77.40 as a covered diagnosis.
Showing top 10 of 537 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing A77.40.
4 Medicare
CPT Codes Commonly Billed with A77.40
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 A77.40 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 |
|---|---|---|
| A77.40 | 08240 | 00000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To A77.40
Other codes in section A75-A79 (Rickettsioses).
ICD-10 A77.40, Billing FAQ
Is ICD-10 code A77.40 billable? +
Yes, A77.40 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
Is A77.40 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 A77.40 map to? +
Per CMS GEMs, A77.40 maps to ICD-9 codes: 08240. 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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