A70 — Chlamydia psittaci infections
Is A70 billable?
Yes — A70 is billable for FY2027. A70 is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. A70 may be submitted for encounters from October 1, 2026 through September 30, 2027.
A70 at a glance
| Code | A70 |
|---|---|
| Description | Chlamydia psittaci infections |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Which MS-DRGs does A70 group to?
A70 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, A70 is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG.
How is A70 listed in the Alphabetic Index?
These are the routes through the Alphabetic Index that lead to A70. They show the wording a clinician may have documented, which often differs from the Tabular description.
- Ornithosis
- Parrot fever
- Psittacosis
- Chlamydia, chlamydial › psittaci
- Fever › parrot (inanition) (of unknown origin) (persistent) (with chills) (with rigor)
- Pneumonia › psittacosis (acute) (double) (migratory) (purulent) (septic) (unresolved)
- Infection, infected, infective › Chlamydia, chlamydial › psittaci (opportunistic)
- Pneumonia › in › ornithosis (acute) (double) (migratory) (purulent) (septic) (unresolved)
- Pneumonia › in › psittacosis (acute) (double) (migratory) (purulent) (septic) (unresolved)
Inclusion terms
Alternative wording in documentation that is classified to A70.
- Ornithosis
- Parrot fever
- Psittacosis
Excludes1 — never code together — inherited from A70-A74
The conditions below can never be reported together with A70 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
- sexually transmitted chlamydial diseases (A55-A56)
Use additional code — inherited from Chapter 1
Report an additional code alongside A70 to fully describe the condition. A70 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 A70, but a patient may have both at the same time. When documentation supports it, A70 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 A70 existed?
A70 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 A70?
ICD-10-CM declares these codes mutually exclusive with A70 — exactly one of each pair can be correct for a given encounter.