A49.01 — Methicillin susceptible Staphylococcus aureus infection, unspecified site
Is A49.01 billable?
Yes, but A49.01 is an unspecified code. A49.01 is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, A49.01 is an unspecified or catch-all code. Payers apply additional scrutiny to unspecified codes and many deny them when the medical record supports a more specific option, so check the documentation before selecting A49.01 — the more specific alternatives are listed below.
More specific alternatives
A49.01 at a glance
| Code | A49.01 |
|---|---|
| Description | Methicillin susceptible Staphylococcus aureus infection, unspecified site |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Which MS-DRGs does A49.01 group to?
A49.01 sits in MDC 18 and helps define the logic of 3 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 867Other Infectious and Parasitic Diseases Diagnoses with MCCmedical
- 868Other Infectious and Parasitic Diseases Diagnoses with CCmedical
- 869Other Infectious and Parasitic Diseases Diagnoses without CC/MCCmedical
How is A49.01 listed in the Alphabetic Index?
These are the routes through the Alphabetic Index that lead to A49.01. They show the wording a clinician may have documented, which often differs from the Tabular description.
- MSSA › infection (Methicillin susceptible Staphylococcus aureus)
- Infection, infected, infective › methicillin › susceptible Staphylococcus aureus (opportunistic)
- Infection, infected, infective › staphylococcal, unspecified site › aureus (opportunistic)
Inclusion terms
Alternative wording in documentation that is classified to A49.01.
- Methicillin susceptible Staphylococcus aureus (MSSA) infection
- Staphylococcus aureus infection NOS
Excludes1 — never code together — inherited from A49
The conditions below can never be reported together with A49.01 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
Use additional code — inherited from Chapter 1
Report an additional code alongside A49.01 to fully describe the condition. A49.01 is sequenced first.
- code to identify resistance to antimicrobial drugs (Z16.-)
Excludes2 — not included here — inherited from Chapter 1
The conditions below are not part of A49.01, but a patient may have both at the same time. When documentation supports it, A49.01 and the excluded code may both 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)
Excludes2 — not included here — inherited from A49
The conditions below are not part of A49.01, but a patient may have both at the same time. When documentation supports it, A49.01 and the excluded code may both be reported.
- chlamydial infection NOS (A74.9)
How long has A49.01 existed?
A49.01 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.