A90 — Dengue fever [classical dengue]
Is A90 billable?
Yes — A90 is billable for FY2027. A90 is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. A90 may be submitted for encounters from October 1, 2026 through September 30, 2027.
A90 at a glance
| Code | A90 |
|---|---|
| Description | Dengue fever [classical dengue] |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Which MS-DRGs does A90 group to?
A90 sits in MDC 18 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.
- 865Viral Illness with MCCmedical
- 866Viral Illness without MCCmedical
As a secondary diagnosis, A90 is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG.
How is A90 listed in the Alphabetic Index?
These are the routes through the Alphabetic Index that lead to A90. They show the wording a clinician may have documented, which often differs from the Tabular description.
- Dengue (classical) (fever)
- Fever › Aden (inanition) (of unknown origin) (persistent) (with chills) (with rigor)
- Fever › breakbone (inanition) (of unknown origin) (persistent) (with chills) (with rigor)
- Fever › dandy (inanition) (of unknown origin) (persistent) (with chills) (with rigor)
- Fever › dengue (inanition) (of unknown origin) (persistent) (with chills) (with rigor)
- Fever › solar (inanition) (of unknown origin) (persistent) (with chills) (with rigor)
- Fever › sun (inanition) (of unknown origin) (persistent) (with chills) (with rigor)
- Fever › seven day › dengue (inanition) (of unknown origin) (persistent) (with chills) (with rigor)
Excludes1 — never code together
The conditions below can never be reported together with A90 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
- dengue hemorrhagic fever (A91)
Use additional code — inherited from Chapter 1
Report an additional code alongside A90 to fully describe the condition. A90 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 A90, but a patient may have both at the same time. When documentation supports it, A90 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)
How long has A90 existed?
A90 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 A90?
ICD-10-CM declares these codes mutually exclusive with A90 — exactly one of each pair can be correct for a given encounter.