2027 ICD-10-CM Diagnosis Code A69.23Arthritis due to Lyme disease

ICD-10-CM Codes›A00–B99›A65-A69›A69

ICD-10-CM A69.23
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

A69.23 is a billable ICD-10-CM diagnosis code for arthritis due to Lyme disease. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 867 through 869. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 56 closely related codes. Coders also document this condition as arthritis caused by Spirochaetales. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Infective arthritis; and Parasitic, other specified and unspecified infections.

For Medicare Advantage risk adjustment, A69.23 maps to CMS-HCC Category 92 (Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis) under the V28 model, adding a risk factor of about 0.479 for a community, non-dual, aged beneficiary in payment year 2027.

Code Identity

ICD-10-CM Code
A69.23
Billable Status
Yes — Valid for Submission
Code Describes
Arthritis due to Lyme disease
Short Description
Arthritis due to Lyme disease
Same as the full description in the CMS dataset.
Parent Code
Lyme disease

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA65-A69Other spirochetal diseases
CategoryA69Other spirochetal infections
This CodeA69.23Arthritis due to Lyme disease

Medicare Risk Adjustment (HCC)Billing

A69.23 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.

CMS-HCC V28 Category (Payment Model)
HCC 92— Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis
Payment HCC · PY 2027 one of 609 ICD-10-CM codes in this category
Risk Adjustment Factor (RAF) Weight
+0.479
community, non-dual, aged · ranges 0.471–0.632 across segments
Hierarchy
Top of its hierarchy
HCC 92 is not superseded by any other condition category
Prior Model (CMS-HCC V24)
HCC 39
V24 retired V28 pays 100% of MA risk scores since PY 2026
Other CMS Models
PACE (CMS-HCC V22): HCC 39 · ESRD (V21): HCC 39 · ESRD (V24): HCC 39
ESRD V21 weights: 0.061 dialysis, 0.375–0.468 functioning graft · ESRD V24 weights: 0.092 dialysis, 0.431–0.578 functioning graft
Part D (RxHCC)
Not mapped
A69.23 does not risk-adjust in the RxHCC prescription drug model

Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Arthritis caused by Spirochaetales
  • Lyme arthritis
  • Lyme arthritis of knee joint
  • Skeletal Lyme disease

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to A69.23: its own notes plus those printed at block A65-A69 and Chapter 1. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • diseases generally recognized as communicable or transmissible

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Block A65-A69 Other spirochetal diseases applies to 28 codes
From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • 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)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • code to identify resistance to antimicrobial drugs (Z16.-)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name A69.23, its category, or a range that includes it.

Excludes1 2

These codes carry an Excludes1 note naming A69.23: they are not reported together with it, unless the two conditions are unrelated.

  • M01 Direct infections of joint in infectious and parasitic diseases classified elsewhere
    arthropathy in Lyme disease (A69.23)
  • Block L49-L54 Urticaria and erythema
    Lyme disease (A69.2-) names A69.2-, which includes this code

Excludes2 1

These codes carry an Excludes2 note naming A69.23: its condition is not part of those codes, and both may be reported when the patient has both.

  • A68 Relapsing fevers
    Lyme disease (A69.2-) names A69.2-, which includes this code

Index to Diseases and InjuriesGuidance

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR MUS001
Infective arthritis
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR INF009
Parasitic, other specified and unspecified infections
Default principal diagnosis: inpatient No · outpatient No

Clinical InformationClinical

  • Lyme Disease

    an infectious disease caused by a spirochete, borrelia burgdorferi, which is transmitted chiefly by ixodes dammini (see ixodes) and pacificus ticks in the united states and ixodes ricinis (see ixodes) in europe. it is a disease with early and late cutaneous manifestations plus involvement of the nervous system, heart, eye, and joints in variable combinations. the disease was formerly known as lyme arthritis and first discovered at old lyme, connecticut.

Patient EducationClinical

Infectious Arthritis

Most kinds of arthritis cause pain and swelling in your joints. Joints are places where two bones meet, such as your elbow or knee. Infectious arthritis is an infection in the joint. The infection comes from a bacterial, viral, or fungal infection that spreads from another part of the body. Symptoms of infectious arthritis include:

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert A69.23 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
088.81 Lyme disease
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About A69.23Overview

What is the ICD-10 code for arthritis due to Lyme disease?

The ICD-10-CM code for arthritis due to Lyme disease is A69.23 (sometimes written as A6923). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is A69.23 (Lyme disease) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report arthritis due to Lyme disease on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does A69.23 group to?

When arthritis due to Lyme disease is the principal diagnosis on an inpatient stay, it groups to MS-DRG 867, 869, 868, with relative weights from 0.6784 to 2.1855 depending on complications. Higher weights mean higher Medicare reimbursement.

Is A69.23 a CC or MCC?

CMS lists A69.23 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 56 closely related codes in its exclusion list.

What is the ICD-9 equivalent of A69.23?

Under the General Equivalence Mappings, arthritis due to Lyme disease converts to ICD-9-CM 088.81 (Lyme disease). The mapping is approximate, so confirm the match fits the documentation.

What HCC is A69.23?

A69.23 (arthritis due to Lyme disease) maps to CMS-HCC Category 92 (Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis), commonly written as HCC 92, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 39 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. It does not map to any RxHCC in the Part D prescription drug model.

Does A69.23 risk-adjust for Medicare Advantage payment?

Yes. When documented and reported on a Medicare Advantage encounter, A69.23 adds a risk adjustment factor of about 0.479 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.471 to 0.632 depending on the payment segment). HCC 92 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 92 category page.