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Q84.5 ICD-10-CM Code: Enlarged and hypertrophic nails

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

Coding at a Glance

Tabular directives
2 inclusion terms

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 606 — MINOR SKIN DISORDERS WITH MCC (MDC 09)
  • MS-DRG 607 — MINOR SKIN DISORDERS WITHOUT MCC (MDC 09)

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 Q84.5 in the official ICD-10-CM tabular list, quoted as published.

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

Inclusion Terms

Alternative terms the tabular list files under this code.

  • Congenital onychauxis
  • Pachyonychia

Code Overview

Enlarged and hypertrophic nails is a billable ICD-10-CM diagnosis code (Q84.5).

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 (4)

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

Other codes that name Q84.5 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 16 Excludes1 notes across 2 chapters: L60 — Nail disorders (via Q84.-), L60-L75 — Disorders of skin appendages (L60-L75) (via Q84.-), L62 — Nail disorders in diseases classified elsewhere (via Q84.-), L63 — Alopecia areata (via Q84.-), L64 — Androgenic alopecia (via Q84.-), L65 — Other nonscarring hair loss (via Q84.-), L66 — Cicatricial alopecia [scarring hair loss] (via Q84.-), L67 — Hair color and hair shaft abnormalities (via Q84.-), L68 — Hypertrichosis (via Q84.-), L70 — Acne (via Q84.-), L71 — Rosacea (via Q84.-), L72 — Follicular cysts of skin and subcutaneous tissue (via Q84.-), L73 — Other follicular disorders (via Q84.-), L74 — Eccrine sweat disorders (via Q84.-), L75 — Apocrine sweat disorders (via Q84.-), P83 — Other conditions of integument specific to newborn (via Q84.-).

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

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 2 MS-DRGs: DRG 606 (MDC 09), DRG 607 (MDC 09).

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

Clinical classification (AHRQ CCSR):MAL010 — Other specified and unspecified congenital anomalies (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 (Other specified and unspecified congenital anomalies).

Q83.1 — Accessory breast, Q83.2 — Absent nipple, Q83.3 — Accessory nipple, Q83.8 — Other congenital malformations of breast, Q83.9 — Congenital malformation of breast, unspecified, Q84.0 — Congenital alopecia, Q84.1 — Congenital morphological disturbances of hair, not elsewhere classified, Q84.2 — Other congenital malformations of hair, Q84.3 — Anonychia, Q84.4 — Congenital leukonychia, Q84.6 — Other congenital malformations of nails, Q84.8 — Other specified congenital malformations of integument, Q84.9 — Congenital malformation of integument, unspecified, Q85.1 — Tuberous sclerosis, Q85.8 — Other phakomatoses, not elsewhere classified, Q85.81 — PTEN hamartoma tumor syndrome, Q85.82 — Other Cowden syndrome, Q85.83 — Von Hippel-Lindau syndrome, Q85.89 — Other phakomatoses, not elsewhere classified, Q85.9 — Phakomatosis, unspecified, +59 more

Same Index main term, other category

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

Q43.0 — Meckel's diverticulum (displaced) (hypertrophic) (Meckel's diverticulum), Q43.2 — Other congenital functional disorders of colon (colon, congenital), Q44.79 — Other congenital malformations of liver (liver, congenital), Q45.3 — Other congenital malformations of pancreas and pancreatic duct (pancreas, congenital), Q51.828 — Other congenital malformations of cervix (cervix, congenital), Q52.4 — Other congenital malformations of vagina (hymen, congenital), Q52.6 — Congenital malformation of clitoris (clitoris, congenital), Q55.29 — Other congenital malformations of testis and scrotum (testis, congenital), Q55.4 — Other congenital malformations of vas deferens, epididymis, seminal vesicles and prostate (prostate, congenital), Q63.3 — Hyperplastic and giant kidney (kidney, congenital), Q67.4 — Other congenital deformities of skull, face and jaw (hemifacial), Q74.1 — Congenital malformation of knee (meniscus, knee, congenital), Q74.2 — Other congenital malformations of lower limb(s), including pelvic girdle (toe), Q79.1 — Other congenital malformations of diaphragm (hiatus), R16.0 — Hepatomegaly, not elsewhere classified (liver), R23.4 — Changes in skin texture (skin), R59.0 — Localized enlarged lymph nodes (hilus gland), R59.1 — Generalized enlarged lymph nodes (gland, glandular, generalized), R59.9 — Enlarged lymph nodes, unspecified (gland, glandular), R93.89 — Abnormal findings on diagnostic imaging of other specified body structures (endometrium), +103 more

Contextual Map

Every relationship of Q84.5 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 Q84.5 with these 8 related codes in Claim Check

Hierarchy

Referenced by Excludes1 notes (16)

Clinical classification (CCSR)

MS-DRG Grouper

MDC crossing

  • MDC 09 — Diseases and Disorders of the Skin, Subcutaneous Tissue and Breast[MDC crossing]: “Diseases and Disorders of the Skin, Subcutaneous Tissue and Breast — 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. 7,376 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Index entries

  • Hypertrophy, hypertrophic, nail, congenital[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Onychauxis, congenital[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Pachyonychia (congenital)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Thickening, nail, congenital[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes (9)

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. "Q84.5 — Enlarged and hypertrophic nails." ICD-10-CM FY2026. https://medcoder.ai/icd10/code/q84.5-enlarged-and-hypertrophic-nails

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Enlarged and hypertrophic nails

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 Q84.5 in its code family, with their registry titles.

View all codes in the Q84 family