A70 ICD-10-CM Code: Chlamydia psittaci infections
A70 is not a CMS-HCC payment code. MEAT criteria · RAF Calculator · HCC coding software
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FY 2026 Apr update / Certain infectious and parasitic diseases (A00-B99) / Other diseases caused by chlamydiae (A70-A74)
A70
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceChlamydia psittaci infections
This is a bacterial infection caused by Chlamydia psittaci, typically transmitted from infected birds to humans through inhalation of contaminated dust or respiratory secretions. The infection commonly causes pneumonia and flu-like symptoms in affected individuals.
CMS-HCC V28
N/A—
Not mapped
CMS-HCC V24
HistoricalHistorical
Not used for CY2026 payment
ACA/HHS
N/A—
Not mapped
ESRD/PACE
N/A—
Not mapped
RXHCC
N/A—
Not mapped
Code Book Path
Inclusion Terms
Official- Ornithosis
- Parrot fever
- Psittacosis
Excludes 2
Official- carrier or suspected carrier of infectious disease (Z22.-)Inherited from A00-B99
- infectious and parasitic diseases complicating pregnancy, childbirth and the puerperium (O98.-)Inherited from A00-B99
- infectious and parasitic diseases specific to the perinatal period (P35-P39)Inherited from A00-B99
- influenza and other acute respiratory infections (J00-J22)Inherited from A00-B99
Related Codes
No related codes are included in this display for A70. Check the Code Book for the complete code path.
Includes
Official- diseases generally recognized as communicable or transmissibleInherited from A00-B99
Excludes 1
Official- certain localized infections - see body system-related chaptersInherited from A00-B99, A70-A74
- sexually transmitted chlamydial diseases (A55-A56)Inherited from A00-B99, A70-A74
Code First
OfficialNo Code First sequencing instructions are included in this display for A70. Check the code and parent instructions in the Code Book.
Use Additional
Official- code to identify resistance to antimicrobial drugs (Z16.-)Inherited from A00-B99
Code Also
OfficialNo Code Also instructions are included in this display for A70. Check the code and parent instructions in the Code Book.
Buddy Documentation Tip
Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →
Is A70 an HCC code?
No. A70 is a billable ICD-10-CM code with no mapping under the current CMS-HCC V28 community payment model, and none under the ESRD, Part D RxHCC, or HHS-HCC models.
- Code
- A70
- Description
- Chlamydia psittaci infections
- HCC (V28)
- No CMS-HCC V28 mapping
- RAF reference coefficient
- —
- Billable
- Yes
- Payment year
- 2026
Coder workflow notes
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What This Code Means
A70 is the ICD-10-CM diagnosis code for chlamydia psittaci infections. This is a bacterial infection caused by Chlamydia psittaci, typically transmitted from infected birds to humans through inhalation of contaminated dust or respiratory secretions. The infection commonly causes pneumonia and flu-like symptoms in affected individuals. A70 sits in the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99), within the section covering other diseases caused by chlamydiae (a70-a74).
A70 is a billable ICD-10-CM code, but no current CMS-HCC V28 community payment mapping is shown, and none under the ESRD, Part D RxHCC, or HHS-HCC models. Do not assign risk adjustment value from this page when no source-backed mapping is shown; verify the applicable model and payment year.
Verify the specific site of infection (respiratory tract, systemic, etc.) as A70 is the parent code; additional specificity codes may be needed depending on documentation.
HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for A70 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Verify the specific site of infection (respiratory tract, systemic, etc.) as A70 is the parent code; additional specificity codes may be needed depending on documentation
- •Document the source of exposure (bird contact, occupational exposure) as this helps establish the diagnosis and may be relevant for public health reporting