What is ICD-10 code A69.21?

A69.21 is the ICD-10-CM diagnosis code for Meningitis due to Lyme disease. It belongs to the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99). A69.21 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. A69.21 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. A69.21 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. A69.21 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

Which HCC does A69.21 map to under V28?

A69.21 has no payable CMS-HCC V28 mapping in the final FY2026 CMS file.

What RAF reference is published for A69.21?

A69.21 has no V28 reference coefficient because the final FY2026 source verifies no payable V28 mapping.

What is the V28 vs V24 difference for A69.21?

A69.21 has verified no payable V28 mapping in the final FY2026 source. Select a historical effective period before making any V24 comparison.

2026 ICD-10-CM A69.21: Meningitis due to Lyme disease

A69.21 is not a CMS-HCC payment code. MEAT criteria · RAF Calculator · HCC Buddy coding tools

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Code lookupA69.21

Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Certain infectious and parasitic diseases (A00-B99) / Other spirochetal diseases (A65-A69)

A69.21

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Meningitis due to Lyme disease

This is a serious infection of the protective membranes surrounding the brain and spinal cord caused by Lyme disease, which is transmitted through tick bites. It occurs when the bacteria that causes Lyme disease spreads to the central nervous system.

Overview Risk Models Code Book Documentation Audit Notes Edition comparison

CMS-HCC V28

N/A

—

Not risk-adjusted for this model/period.

Not mapped

CMS-HCC V24

Historical

Not used for standard CY2026 Medicare Advantage payment. Select a historical period to review V24.

Not used for CY2026 payment

ACA/HHS

Mapped

HCC 003

HHS-HCC 003 adult, RAF varies...

Code-level coefficient reference

ESRD/PACE

N/A

—

Not risk-adjusted for this model/period.

Not mapped

RXHCC

N/A

—

Not risk-adjusted for this model/period.

Not mapped

Code Book Path

Official

A69Other spirochetal infections A69.2Lyme disease A69.21Meningitis due to Lyme disease

Inclusion Terms

Official

Erythema chronicum migrans due to Borrelia burgdorferiInherited from A69.2

Excludes 2

Official

carrier or suspected carrier of infectious disease (Z22.-)Inherited from A00-B99, A65-A69
infectious and parasitic diseases complicating pregnancy, childbirth and the puerperium (O98.-)Inherited from A00-B99, A65-A69
infectious and parasitic diseases specific to the perinatal period (P35-P39)Inherited from A00-B99, A65-A69
influenza and other acute respiratory infections (J00-J22)Inherited from A00-B99, A65-A69
leptospirosis (A27.-)Inherited from A00-B99, A65-A69
syphilis (A50-A53)Inherited from A00-B99, A65-A69

Related Codes

Official

A69.20Lyme disease, unspecified A69.22Other neurologic disorders in Lyme disease A69.23Arthritis due to Lyme disease A69.29Other conditions associated with Lyme disease

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

Code First

Official

No Code First sequencing instructions are included in this display for A69.21. 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

Official

No Code Also instructions are included in this display for A69.21. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance

Always verify that meningitis is documented as a complication of Lyme disease in the medical record before assigning this code

This code should be used in conjunction with A69.20 (Lyme disease of nervous system) or other Lyme disease codes to provide complete clinical picture

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 A69.21 an HCC code?

A69.21 is not in the CMS-HCC V28 or V24 community payment model. A69.21 also appears in the HHS-HCC commercial risk model (HCC 003 (HHS-HCC 003 adult, RAF varies by metal level)), which is a commercial market model rather than a Medicare Advantage payment mapping.

Code: A69.21
Description: Meningitis due to Lyme disease
HCC (V28): No CMS-HCC V28 mapping
RAF reference coefficient: —
Billable: Yes
Payment year: 2026

Coder workflow notes

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This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).

What This Code Means

A69.21 is the ICD-10-CM diagnosis code for meningitis due to lyme disease. This is a serious infection of the protective membranes surrounding the brain and spinal cord caused by Lyme disease, which is transmitted through tick bites. It occurs when the bacteria that causes Lyme disease spreads to the central nervous system. A69.21 sits in the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99), within the section covering other spirochetal diseases (a65-a69).

A69.21 has no mapping under the CMS-HCC V28 or V24 community payment models. A69.21 also appears in the HHS-HCC commercial risk model (HCC 003 (HHS-HCC 003 adult, RAF varies by metal level)), which is a commercial market model rather than a Medicare Advantage payment mapping. Do not assign V28 risk adjustment value from this page; verify the applicable model and payment year before using this code for risk adjustment.

Always verify that meningitis is documented as a complication of Lyme disease in the medical record before assigning this code.

HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for A69.21 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Always verify that meningitis is documented as a complication of Lyme disease in the medical record before assigning this code
•This code should be used in conjunction with A69.20 (Lyme disease of nervous system) or other Lyme disease codes to provide complete clinical picture