ICD-10 A01.04
Billable / Specific HCC v28: 39 CCTyphoid arthritis
About ICD-10-CM A01.04
ICD-10-CM code A01.04 represents Typhoid arthritis. This is a billable/specific code in the Infectious and Parasitic Diseases chapter (block A01). The 2026 edition of ICD-10-CM A01.04 became effective on October 1, 2025.
Coding Tips for A01.04
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
A01.04 is a CMS-HCC v28 risk-adjustment code (category 39). 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.
A01.04 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.
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 Typhoid arthritis. As a Complication/Comorbidity (CC), this contributes to DRG severity adjustment when documented alongside the principal diagnosis.
Medicare LCD Coverage for A01.04
Local Coverage Determinations (LCDs) from CMS MACs that list A01.04 as a covered diagnosis.
Showing top 10 of 543 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing A01.04.
5 Medicare
CPT Codes Commonly Billed with A01.04
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
- 87482 CMS LCD: Billing and Coding: MolDX: Molecular Syndromic Panels for Infectious Disease Pathogen Identification Testing CMS LCD
- 0429U CMS LCD: Billing and Coding: MolDX: Molecular Syndromic Panels for Infectious Disease Pathogen Identification Testing CMS LCD
- 87557 CMS LCD: Billing and Coding: MolDX: Molecular Syndromic Panels for Infectious Disease Pathogen Identification Testing CMS LCD
- 87593 CMS LCD: Billing and Coding: MolDX: Molecular Syndromic Panels for Infectious Disease Pathogen Identification Testing CMS LCD
- 0068U CMS LCD: Billing and Coding: MolDX: Molecular Syndromic Panels for Infectious Disease Pathogen Identification Testing CMS LCD
- 87651 CMS LCD: Billing and Coding: MolDX: Molecular Syndromic Panels for Infectious Disease Pathogen Identification Testing CMS LCD
- 87487 CMS LCD: Billing and Coding: MolDX: Molecular Syndromic Panels for Infectious Disease Pathogen Identification Testing CMS LCD
- 87538 CMS LCD: Billing and Coding: MolDX: Molecular Syndromic Panels for Infectious Disease Pathogen Identification Testing CMS LCD
- 87563 CMS LCD: Billing and Coding: MolDX: Molecular Syndromic Panels for Infectious Disease Pathogen Identification Testing CMS LCD
- 87582 CMS LCD: Billing and Coding: MolDX: Molecular Syndromic Panels for Infectious Disease Pathogen Identification Testing CMS LCD
Convert A01.04 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 |
|---|---|---|
| A01.04 | 0020 | 10000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To A01.04
Other codes in section A00-A09 (Intestinal infectious diseases).
ICD-10 A01.04, Billing FAQ
Is ICD-10 code A01.04 billable? +
Yes, A01.04 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
Does A01.04 affect Medicare Advantage HCC risk adjustment? +
Yes. A01.04 maps to CMS-HCC v28 category 39. Capture this diagnosis annually for accurate Medicare Advantage risk score.
Is A01.04 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 A01.04? +
Procedures frequently paired with A01.04 include: 87482, 0429U, 87557, 87593, 0068U.
What ICD-9 codes does A01.04 map to? +
Per CMS GEMs, A01.04 maps to ICD-9 codes: 0020. 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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