2027 ICD-10-CM Diagnosis Code A48.3Toxic shock syndrome
ICD-10-CM Codes›A00–B99›A30-A49›A48
- Billable — Valid for Submission
- MCC — Major Complication or Comorbidity
- Risk Adjusts — HCC 2
- Not Chronic
A48.3 is a billable ICD-10-CM diagnosis code for toxic shock syndrome. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 867 through 869. 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 49 closely related codes. Coders also document this condition as septic shock co-occurrent with acute organ dysfunction caused by methicillin resistant Staphylococcus aureus. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Bacterial infections.
For Medicare Advantage risk adjustment, A48.3 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
A48.3 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.
- Septic shock co-occurrent with acute organ dysfunction caused by methicillin resistant Staphylococcus aureus
- Septic shock co-occurrent with acute organ dysfunction caused by methicillin susceptible Staphylococcus aureus
- Septic shock co-occurrent with acute organ dysfunction caused by Streptococcus
- Septic shock co-occurrent with acute organ dysfunction due to Staphylococcus
- Staphylococcal toxic shock syndrome
- Streptococcal toxic shock syndrome
- Toxic shock syndrome
- Toxic shock syndrome caused by methicillin resistant Staphylococcus aureus infection
- Toxic shock syndrome caused by methicillin susceptible Staphylococcus aureus
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to A48.3: its own notes plus those printed at A48 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.
- diseases generally recognized as communicable or transmissible
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
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 A48.3, its category, or a range that includes it.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
toxic, syndrome A48.3
Syndrome See Also: Disease;
toxic A48.3
toxic shock A48.3
Toxic (poisoning) See Also: condition; T65.91
shock syndrome A48.3
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Toxic Shock Syndrome
a rare acute life-threatening systemic bacterial noncontagious illness caused by any of several related staphylococcal exotoxins. it is characterized by high fever, hypotension, rash, multi-organ dysfunction, and cutaneous desquamation during the early convalescent period. the toxins affect the host immune system, causing an exuberant and pathological host inflammatory response. laboratory findings include leukocytosis, elevated prothrombin time, hypoalbuminemia, hypocalcemia, and pyuria.
Patient EducationClinical
Sepsis
Sepsis is your body's overactive and extreme response to an infection. Sepsis is a life-threatening medical emergency. Without quick treatment, it can lead to tissue damage, organ failure, and even death.
The full article covers:
- What is sepsis?
- What causes sepsis?
- Who is more likely to develop sepsis?
- What are the symptoms of sepsis?
- What other problems can sepsis cause?
- How is sepsis diagnosed?
- What are the treatments for sepsis?
- Can sepsis be prevented?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert A48.3 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About A48.3Overview
What is the ICD-10 code for toxic shock syndrome?
The ICD-10-CM code for toxic shock syndrome is A48.3 (sometimes written as A483). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is A48.3 (Other bacterial diseases, not elsewhere classified) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report toxic shock syndrome on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does A48.3 group to?
When toxic shock syndrome is the principal diagnosis on an inpatient stay, it groups to MS-DRG 867, 869, 868, with relative weights from 0.6784 to 2.1855 depending on complications. Higher weights mean higher Medicare reimbursement.
Is A48.3 a CC or MCC?
CMS lists A48.3 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 49 closely related codes in its exclusion list.
Can A48.3 be reported with R57.8?
Not as a rule. The Excludes1 note on A48.3 lists "endotoxic shock NOS (R57.8)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
What HCC is A48.3?
A48.3 (toxic shock syndrome) 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 A48.3 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, A48.3 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.
