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R29.2 ICD-10-CM Code: Abnormal reflex

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

Coding at a Glance

Tabular directives
3 Excludes2

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 v43, Appendix B.

  • MS-DRG 091 — OTHER DISORDERS OF NERVOUS SYSTEM WITH MCC (MDC 01)
  • MS-DRG 092 — OTHER DISORDERS OF NERVOUS SYSTEM WITH CC (MDC 01)
  • MS-DRG 093 — OTHER DISORDERS OF NERVOUS SYSTEM WITHOUT CC/MCC (MDC 01)

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 R29.2 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025

Excludes2 — Not Included Here

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

Coder workflow for R29.2

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

Before you code R29.2

  1. Check whether an established diagnosis that explains this sign or symptom is documented. If one is, review whether the documented diagnosis changes the coding pathway: a symptom that is integral to a confirmed diagnosis is not reported separately, while one not routinely associated with it may be. Signs and symptoms are reported when no definitive diagnosis is established (Guidelines I.B.4, I.B.5, I.B.6, I.C.18.b).

    Guide: Symptom code vs confirmed diagnosis →

Choose the right path

  1. Is an established diagnosis that explains this sign or symptom documented?
    Yes → Review whether the documented diagnosis changes the coding pathway: a symptom integral to it is not reported separately.
    No → Continue — the sign or symptom code stands when no definitive diagnosis is established.

Consider R29.2. Then confirm the code is valid for the date of service in the Verify section.

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).

Official instructions as workflow

  • Excludes2 — not part of R29.2(3 notes)

    Coding workflow: The conditions named in this note are not included in R29.2. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

    CompareH57.0, J39.2, R55

    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: The sign or symptom is documented, and the same record establishes a diagnosis that routinely includes it.

Coding question: Is R29.2 reported in addition to the diagnosis?

Path: Review the documented diagnosis and whether the classification treats this finding as integral to it.

Reason: Signs and symptoms integral to a confirmed diagnosis are not coded separately; those not routinely associated with it may be reported when present (Guidelines I.B.5, I.B.6, I.C.18.b).

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.

Code Overview

Abnormal reflex is a billable ICD-10-CM diagnosis code (R29.2).

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

Indexed Clinical Terms (10)

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.

Verify Before Coding

  • No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.

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 structured relationships — computed from published CMS and AHRQ datasets

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

FY2026 MS-DRG: not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity for that release.

Named in the grouper logic of 3 MS-DRGs: DRG 091 (MDC 01), DRG 092 (MDC 01), DRG 093 (MDC 01).

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

Clinical classification (AHRQ CCSR):SYM010 — Nervous system signs and symptoms (default).

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 category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Nervous system signs and symptoms).

R26.1 — Paralytic gait, R26.2 — Difficulty in walking, not elsewhere classified, R26.81 — Unsteadiness on feet, R26.89 — Other abnormalities of gait and mobility, R26.9 — Unspecified abnormalities of gait and mobility, R27.0 — Ataxia, unspecified, R27.8 — Other lack of coordination, R27.9 — Unspecified lack of coordination, R29.0 — Tetany, R29.1 — Meningismus, R29.5 — Transient paralysis, R29.810 — Facial weakness, R29.818 — Other symptoms and signs involving the nervous system, R29.90 — Unspecified symptoms and signs involving the nervous system, R40.2110 — Coma scale, eyes open, never, unspecified time, R40.2111 — Coma scale, eyes open, never, in the field [EMT or ambulance], R40.2112 — Coma scale, eyes open, never, at arrival to emergency department, R40.2113 — Coma scale, eyes open, never, at hospital admission, R40.2114 — Coma scale, eyes open, never, 24 hours or more after hospital admission, R40.2120 — Coma scale, eyes open, to pain, unspecified time, +138 more

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main terms “Poor”, “Abnormal, abnormality, abnormalities”, “Disturbance”, …; these codes share that main term but sit in a different category of the Tabular List.

R20.3 — Hyperesthesia (sensation NEC, skin, hyperesthesia), R20.8 — Other disturbances of skin sensation (temperature, sense), R20.9 — Unspecified disturbances of skin sensation (sensation NEC), R25.0 — Abnormal head movements (head movement), R25.1 — Tremor, unspecified (movement, involuntary, tremor), R25.2 — Cramp and spasm (movement, involuntary, spasm), R25.3 — Fasciculation (movement, involuntary, fasciculation), R25.8 — Other abnormal involuntary movements (movement, involuntary, specified type NEC), R25.9 — Unspecified abnormal involuntary movements (movement, involuntary), R27.8 — Other lack of coordination (coordination), R39.12 — Poor urinary stream (urinary stream), R39.198 — Other difficulties with micturition (urination NEC), R42 — Dizziness and giddiness (equilibrium), R43.0 — Anosmia (sensation NEC, smell, anosmia), R43.1 — Parosmia (olfactory nerve), R43.2 — Parageusia (sensation NEC, taste, parageusia), R43.8 — Other disturbances of smell and taste (sensation NEC, smell, and taste), R43.9 — Unspecified disturbances of smell and taste (sensation NEC, taste), R45.0 — Nervousness (nervous, functional), R46.0 — Very low level of personal hygiene (personal hygiene), +396 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.

Blood Glucose Test, Thyroid Stimulating Hormone (TSH)

Contextual Map

Every relationship of R29.2 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 R29.2 with these 3 related codes in Claim Check

Hierarchy

Excludes2

Clinical classification (CCSR)

MS-DRG Grouper

MDC crossing

  • MDC 01 — Diseases and Disorders of the Nervous System[MDC crossing]: “Diseases and Disorders of the Nervous System — 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. 8,892 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Index entries (10)

  • Abnormal, abnormality, abnormalities, knee jerk[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Abnormal, abnormality, abnormalities, plantar reflex[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Areflexia[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Disorder (of), reflex[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Disturbance (s), motor[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Disturbance (s), reflex[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Hyper-reflexia[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Hyporeflexia[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • and 2 more

Nearest codes (40)

Change history

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

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 FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v43.1 (April 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 — v43 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 structured 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 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.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

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. "R29.2 — Abnormal reflex." ICD-10-CM FY2026. https://medcoder.ai/icd10/code/r29.2-abnormal-reflex

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Abnormal reflex

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027 (effective October 1, 2026), 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 R29.2 in its code family, with their registry titles.

View all codes in the R29 family