ICD-10 A22.1
Billable / Specific HCC v28: 115 MCCPulmonary anthrax
About ICD-10-CM A22.1
ICD-10-CM code A22.1 represents Pulmonary anthrax. This is a billable/specific code in the Infectious and Parasitic Diseases chapter (block A22). The 2026 edition of ICD-10-CM A22.1 became effective on October 1, 2025.
Coding Tips for A22.1
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
A22.1 is a CMS-HCC v28 risk-adjustment code (category 115). 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.
A22.1 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.
Inclusion Terms / Approximate Synonyms
Clinical terms and conditions classified under A22.1. Per CMS ICD-10-CM Tabular 2026.
- Inhalation anthrax
- Ragpicker's disease
- Woolsorter's disease
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 Pulmonary anthrax. As a Major Complication/Comorbidity (MCC), this can shift the DRG assignment to a higher-weighted category, substantial reimbursement impact.
Medicare LCD Coverage for A22.1
Local Coverage Determinations (LCDs) from CMS MACs that list A22.1 as a covered diagnosis.
Showing top 10 of 84 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing A22.1.
3 Aetna
5 Medicare
CPT Codes Commonly Billed with A22.1
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
- 94726 CMS LCD: Billing and Coding: Respiratory Therapy (Respiratory Care) CMS LCD
- 94004 CMS LCD: Billing and Coding: Respiratory Therapy (Respiratory Care) CMS LCD
- 94621 CMS LCD: Billing and Coding: Respiratory Therapy (Respiratory Care) CMS LCD
- 94011 CMS LCD: Billing and Coding: Respiratory Therapy (Respiratory Care) CMS LCD
- 94003 CMS LCD: Billing and Coding: Respiratory Therapy (Respiratory Care) CMS LCD
- 94668 CMS LCD: Billing and Coding: Respiratory Therapy (Respiratory Care) CMS LCD
- 94070 CMS LCD: Billing and Coding: Respiratory Therapy (Respiratory Care) CMS LCD
- 94664 CMS LCD: Billing and Coding: Respiratory Therapy (Respiratory Care) CMS LCD
- 94012 CMS LCD: Billing and Coding: Respiratory Therapy (Respiratory Care) CMS LCD
- 31502 CMS LCD: Billing and Coding: Respiratory Therapy (Respiratory Care) CMS LCD
Convert A22.1 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 |
|---|---|---|
| A22.1 | 0221 | 10000 |
| A22.1 | 0221 | 10111 |
| A22.1 | 4845 | 10112 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To A22.1
Other codes in section A20-A28 (Certain zoonotic bacterial diseases).
ICD-10 A22.1, Billing FAQ
Is ICD-10 code A22.1 billable? +
Yes, A22.1 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
What other names or terms map to A22.1? +
ICD-10 A22.1 includes: Inhalation anthrax; Ragpicker's disease; Woolsorter's disease.
Does A22.1 affect Medicare Advantage HCC risk adjustment? +
Yes. A22.1 maps to CMS-HCC v28 category 115. Capture this diagnosis annually for accurate Medicare Advantage risk score.
Is A22.1 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 CPT codes are commonly billed with A22.1? +
Procedures frequently paired with A22.1 include: 94726, 94004, 94621, 94011, 94003.
What ICD-9 codes does A22.1 map to? +
Per CMS GEMs, A22.1 maps to ICD-9 codes: 0221, 0221, 4845. 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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