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

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Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

Tabular directives
2 Excludes2

Billable · FY2027A valid, specific ICD-10-CM code, reportable for dates of service in FY2027.

What you need to know

Source: CMS/NCHS Official ICD-10-CM tabular notes, quoted. From the CMS/NCHS tabular list for the release in force. A note the category or block publishes applies to this code too; the Instructions section marks which is which.

Excludes2Not included here; may be reported together
  • leptospirosis (A27.-)
  • syphilis (A50-A53)

Most relevant related codes MedCoder-derived

Read off the official notes above and this code’s own position in the tabular list. Which to report is a documentation question; Compare shows the two side by side.

CompareCheck ClaimView Related Codes

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v44, Appendix B.

  • MS-DRG 867 — OTHER INFECTIOUS AND PARASITIC DISEASES DIAGNOSES WITH MCC (MDC 18)
  • MS-DRG 868 — OTHER INFECTIOUS AND PARASITIC DISEASES DIAGNOSES WITH CC (MDC 18)
  • MS-DRG 869 — OTHER INFECTIOUS AND PARASITIC DISEASES DIAGNOSES WITHOUT CC/MCC (MDC 18)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for A69.21 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2027Effective: October 1, 2026

Trace:FY2027 changesChange historyRelease, file and checksum

Notes without a marker are published on A69.21 itself; “inherited from” names the category or block whose note applies here.

Excludes2 — Not Included Here

Conditions not covered by this code, but which may be reported alongside it when both are present.

Source: inherited from A65-A69

Coder workflow for A69.21

MedCoder structured workflow — derived from this code’s own official record

Before you code A69.21

  1. A69.21’s title joins a condition with an associated condition or complication. Confirm each component is documented. Where the classification presumes the link through the “with” convention, only a provider statement that the conditions are unrelated defeats it. A combination code is assigned only when it fully identifies the documented conditions; a required second code for the stage, type or manifestation is still reported when the notes ask for it (Guidelines I.B.9, I.A.15).

    Guide: Combination codes →

Documentation check

The provider’s diagnostic statement
Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
The associated condition or complication
Whether the associated condition the title names is documented; the “with” convention presumes some links, and a provider statement that the conditions are unrelated defeats it (Guidelines I.A.15).

Official instructions as workflow

  • Excludes2 — not part of A69.21(2 notes)

    Coding workflow: The conditions named in this note are not included in A69.21. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

    CompareA27

    See the official tabular notes · Guidelines I.A.12.b

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Documentation: Only one of the components this code’s title joins is documented.

Coding question: Is A69.21 supported?

Path: Review the code for the documented component on its own.

Reason: A combination code is assigned only when it fully identifies the documented conditions; otherwise the documented component takes its own code (Guidelines I.B.9).

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Don’t confuse A69.21 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of A69.21 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

  • A69.20— Specificity relationship (Review)

    Overlapping diagnoses in the same category.

    Overlapping codes in the same category — the documentation decides which is the more specific fit.

    What moves you there: A record that documents no more than “Lyme disease, unspecified” takes A69.20; specificity in the record moves it back here.

    Full comparison: A69.21 vs A69.20 →

  • A27— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of leptospirosis adds A27; it is not part of this code and both may be reported when both are documented.

    Full comparison: A69.21 vs A27 →

  • A50— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of syphilis adds A50; it is not part of this code and both may be reported when both are documented.

    Full comparison: A69.21 vs A50 →

  • A53— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of syphilis adds A53; it is not part of this code and both may be reported when both are documented.

    Full comparison: A69.21 vs A53 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Coding context

Guidelines, coding notes, decision aids, relationships (with MS-DRG and CCSR classification), hierarchy, HCC, coverage and the context map: what a coder reaches for after the core. Each section names whether it is official source data, a MedCoder-derived relationship or MedCoder editorial.

Code Overview

Meningitis due to Lyme disease is a billable ICD-10-CM diagnosis code (A69.21).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Verify Before Coding

  • CC as a secondary diagnosis (FY2027). Can raise the stay's MS-DRG severity tier.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder-derived relationships — computed from published CMS and AHRQ datasets

Other codes that name A69.21 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 8 Excludes1 notes across 2 chapters: G01 — Meningitis in bacterial diseases classified elsewhere, L49 — Exfoliation due to erythematous conditions according to extent of body surface involved (via A69.2.-), L49-L54 — Urticaria and erythema (L49-L54) (via A69.2.-), L50 — Urticaria (via A69.2.-), L51 — Erythema multiforme (via A69.2.-), L52 — Erythema nodosum (via A69.2.-), L53 — Other erythematous conditions (via A69.2.-), L54 — Erythema in diseases classified elsewhere (via A69.2.-).

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

Referenced by 1 Excludes2 note: A68 — Relapsing fevers (via A69.2.-).

These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.

MS-DRG Grouper Relationships (FY2027)

Potential MS-DRG participation — not a DRG assignment.

FY2027 MS-DRG: CC — Complication or Comorbidity. Reported as a secondary diagnosis, this code raises the stay's MS-DRG severity tier — except when the principal diagnosis is one of 56 clinically related codes on its CMS exclusion list.

Named in the grouper logic of 3 MS-DRGs: DRG 867 (MDC 18), DRG 868 (MDC 18), DRG 869 (MDC 18).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):NVS001 — Meningitis (default); INF009 — Parasitic, other specified and unspecified infections.

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical process (MS-DRG)

Acts as CC — raises the severity of other admissions. CMS groups these diagnoses into one MS-DRG principal-diagnosis exclusion process — a CC/MCC on this list never raises severity when the principal diagnosis is also on it.

A44.0 — Systemic bartonellosis, A44.1 — Cutaneous and mucocutaneous bartonellosis, A44.8 — Other forms of bartonellosis, A44.9 — Bartonellosis, unspecified, A68.0 — Louse-borne relapsing fever, A68.1 — Tick-borne relapsing fever, A68.9 — Relapsing fever, unspecified, A69.20 — Lyme disease, unspecified, A69.22 — Other neurologic disorders in Lyme disease, A69.23 — Arthritis due to Lyme disease, A69.29 — Other conditions associated with Lyme disease, A75.0 — Epidemic louse-borne typhus fever due to Rickettsia prowazekii, A75.1 — Recrudescent typhus [Brill's disease], A75.2 — Typhus fever due to Rickettsia typhi, A75.3 — Typhus fever due to Rickettsia tsutsugamushi, A75.9 — Typhus fever, unspecified, A77.0 — Spotted fever due to Rickettsia rickettsii, A77.1 — Spotted fever due to Rickettsia conorii, A77.2 — Spotted fever due to Rickettsia siberica, A77.3 — Spotted fever due to Rickettsia australis, +35 more

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical categories (Meningitis, Parasitic, other specified and unspecified infections).

A67.1 — Intermediate lesions of pinta, A67.2 — Late lesions of pinta, A67.3 — Mixed lesions of pinta, A67.9 — Pinta, unspecified, A68.0 — Louse-borne relapsing fever, A68.1 — Tick-borne relapsing fever, A68.9 — Relapsing fever, unspecified, A69.0 — Necrotizing ulcerative stomatitis, A69.1 — Other Vincent's infections, A69.20 — Lyme disease, unspecified, A69.22 — Other neurologic disorders in Lyme disease, A69.23 — Arthritis due to Lyme disease, A69.29 — Other conditions associated with Lyme disease, A69.8 — Other specified spirochetal infections, A69.9 — Spirochetal infection, unspecified, A75.0 — Epidemic louse-borne typhus fever due to Rickettsia prowazekii, A75.1 — Recrudescent typhus [Brill's disease], A75.2 — Typhus fever due to Rickettsia typhi, A75.3 — Typhus fever due to Rickettsia tsutsugamushi, A75.9 — Typhus fever, unspecified, +280 more

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main term “Meningitis”; these codes share that main term but sit in a different category of the Tabular List.

A27.81 — Aseptic meningitis in leptospirosis (leptospiral), A32.11 — Listerial meningitis (in, Listeria monocytogenes), A37.90 — Whooping cough, unspecified species without pneumonia (in, whooping cough), A39.0 — Meningococcal meningitis (Neisseria), A42.81 — Actinomycotic meningitis (actinomycotic), A48.8 — Other specified bacterial diseases (in, bacterial disease NEC), A50.41 — Late congenital syphilitic meningitis (syphilitic, congenital), A51.41 — Secondary syphilitic meningitis (syphilitic, acute), A52.13 — Late syphilitic meningitis (syphilitic), A54.81 — Gonococcal meningitis (gonococcal), A80.9 — Acute poliomyelitis, unspecified (poliovirus), A87.0 — Enteroviral meningitis (echovirus), A87.1 — Adenoviral meningitis (adenoviral), A87.2 — Lymphocytic choriomeningitis (lymphocytic), A87.8 — Other viral meningitis (arbovirus), A87.9 — Viral meningitis, unspecified (viral NEC), B00.3 — Herpesviral meningitis (in, herpesvirus), B01.0 — Varicella meningitis (in, varicella), B02.1 — Zoster meningitis (in, zoster), B05.1 — Measles complicated by meningitis (postmeasles), +31 more

Lab tests where this diagnosis supports Medicare coverage (NCD)

Medicare's National Coverage Determination (NCD) program lists this diagnosis as medical justification for these lab tests.

Gamma-glutamyl Transferase (GGT) Test

Contextual Map

Every relationship of A69.21 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run A69.21 with these 9 related codes in Claim Check

Hierarchy

Referenced by Excludes1 notes

Referenced by Excludes2 notes

  • A68 — Relapsing fevers[Excludes2](via A69.2.-): “Lyme disease (A69.2-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2027

Clinical classification (CCSR)

MS-DRG Grouper

MDC crossing

  • MDC 18 — Infectious and Parasitic Diseases, Systemic or Unspecified Sites[MDC crossing]: “Infectious and Parasitic Diseases, Systemic or Unspecified Sites — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 1 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2027

Index entries

  • Meningitis (basal) (basic) (brain) (cerebral) (cervical) (congestive) (diffuse) (hemorrhagic) (infantile) (membranous) (metastatic) (nonspecific) (pontine) (progressive) (simple) (spinal) (subacute) (sympathetic) (toxic), in (due to), Lyme disease[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027

Nearest codes (10)

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Reference

Index terms and tables, published questions and FAQ, every source behind this page with its release and checksum, the date-of-service check and the complete change history.

Indexed Clinical Terms (1)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2027 tabular list, index and tables, effective October 1, 2026 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v44.0 (October 2026) Release, file and checksum · Publisher’s page
Inpatient payment groups Official source data
CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v44 Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder-derived relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder editorial explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Current data releases:ICD-10-CM FY2027 · ICD-10-PCS FY2027 · HCPCS October 2026 · MS-DRG v44 · Medicare Code Editor v44.0 · NCCI PTP Q4 2026 · MUE Q4 2026 · NCD code lists 2026-01 · LCD export September 20, 2026 · All releases and sources

Labels on this page: Official source data · MedCoder-derived relationship · MedCoder editorial explanation. How to read the labels · All data sources and release dates · CMS coding rules

Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "A69.21 — Meningitis due to Lyme disease." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/a69.21-meningitis-due-to-lyme-disease

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Meningitis due to Lyme disease

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027, and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to A69.21 in its code family, with their registry titles.

View all codes in the A69 family