2027 ICD-10-CM Diagnosis Code A22.7Anthrax sepsis
ICD-10-CM Codes›A00–B99›A20-A28›A22
- Billable — Valid for Submission
- MCC — Major Complication or Comorbidity
- Risk Adjusts — HCC 2
- Not Chronic
A22.7 is a billable ICD-10-CM diagnosis code for anthrax sepsis. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 870 through 872. As a secondary diagnosis, it counts as a major complication or comorbidity (MCC) and places an inpatient stay in the highest severity level of its MS-DRG family. It does not count, however, when the principal diagnosis is one of 60 closely related codes. Coders also document this condition as sepsis caused by Bacillus anthracis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Bacterial infections and Septicemia.
For Medicare Advantage risk adjustment, A22.7 maps to CMS-HCC Category 2 (Septicemia, Sepsis, Systemic Inflammatory Response Syndrome/Shock) under the V28 model, adding a risk factor of about 0.500 for a community, non-dual, aged beneficiary in payment year 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
A22.7 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.
Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Sepsis caused by Bacillus anthracis
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to A22.7: its own notes plus those printed at A22 and Chapter 1. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- infection due to Bacillus anthracis
- diseases generally recognized as communicable or transmissible
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
- carrier or suspected carrier of infectious disease (Z22.-)
- certain localized infections - see body system-related chapters
- infectious and parasitic diseases complicating pregnancy, childbirth and the puerperium (O98.-)
- infectious and parasitic diseases specific to the perinatal period (P35-P39)
- influenza and other acute respiratory infections (J00-J22)
Use Additional Code
Add a second code, after this one, to fully describe the condition.
- code to identify resistance to antimicrobial drugs (Z16.-)
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name A22.7, its category, or a range that includes it.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Anthrax
an acute infection caused by the spore-forming bacteria bacillus anthracis. it commonly affects hoofed animals such as sheep and goats. infection in humans often involves the skin (cutaneous anthrax), the lungs (inhalation anthrax), or the gastrointestinal tract. anthrax is not contagious and can be treated with antibiotics.
Patient EducationClinical
Anthrax
Anthrax is a disease caused by Bacillus anthracis, a germ that lives in soil. Many people know about it from the 2001 bioterror attacks. In the attacks, someone purposely spread anthrax through the U.S. mail. This killed five people and made 22 sick.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert A22.7 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About A22.7Overview
What is the ICD-10 code for anthrax sepsis?
The ICD-10-CM code for anthrax sepsis is A22.7 (sometimes written as A227). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is A22.7 (Anthrax) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report anthrax sepsis on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does A22.7 group to?
When anthrax sepsis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 872, 871, 870, with relative weights from 1.0066 to 6.9432 depending on complications. Higher weights mean higher Medicare reimbursement.
Is A22.7 a CC or MCC?
CMS lists A22.7 as an MCC (major complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it places the inpatient stay in the highest-weighted DRG of its severity family. It does not count when the principal diagnosis is one of the 60 closely related codes in its exclusion list.
What is the ICD-9 equivalent of A22.7?
Under the General Equivalence Mappings, anthrax sepsis converts to ICD-9-CM 022.3 (anthrax septicemia) and 995.91 (sepsis). The mapping is approximate, so confirm the match fits the documentation.
What HCC is A22.7?
A22.7 (anthrax sepsis) maps to CMS-HCC Category 2 (Septicemia, Sepsis, Systemic Inflammatory Response Syndrome/Shock), commonly written as HCC 2, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 2 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. It does not map to any RxHCC in the Part D prescription drug model.
Does A22.7 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, A22.7 adds a risk adjustment factor of about 0.500 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.447 to 0.780 depending on the payment segment). HCC 2 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 2 category page.
