I09.1 — Rheumatic diseases of endocardium, valve unspecified
Is I09.1 billable?
Yes, but I09.1 is an unspecified code. I09.1 is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, I09.1 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 I09.1 — the more specific alternatives are listed below.
More specific alternatives
I09.1 at a glance
| Code | I09.1 |
|---|---|
| Description | Rheumatic diseases of endocardium, valve unspecified |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Which MS-DRGs does I09.1 group to?
I09.1 sits in MDC 05 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 306Cardiac Congenital and Valvular Disorders with MCCmedical
- 307Cardiac Congenital and Valvular Disorders without MCCmedical
How is I09.1 listed in the Alphabetic Index?
These are the routes through the Alphabetic Index that lead to I09.1. They show the wording a clinician may have documented, which often differs from the Tabular description.
- Endocarditis › rheumatic (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)
- Endocarditis › with rheumatic fever › inactive or quiescent (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)
- Fever › rheumatic › inactive or quiescent with › endocarditis (inanition) (of unknown origin) (persistent) (with chills) (with rigor)
Excludes1 — never code together
The conditions below can never be reported together with I09.1 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
- endocarditis, valve unspecified (I38)
Inclusion terms
Alternative wording in documentation that is classified to I09.1.
- Rheumatic endocarditis (chronic)
- Rheumatic valvulitis (chronic)
Excludes2 — not included here — inherited from Chapter 9
The conditions below are not part of I09.1, but a patient may have both at the same time. When documentation supports it, I09.1 and the excluded code may both be reported.
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
- systemic connective tissue disorders (M30-M36)
- transient cerebral ischemic attacks and related syndromes (G45.-)
How long has I09.1 existed?
I09.1 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.
Which codes are confused with I09.1?
ICD-10-CM declares these codes mutually exclusive with I09.1 — exactly one of each pair can be correct for a given encounter.