Name: Unspecified juvenile rheumatoid arthritis, left hand
Creator: MedCoder.ai

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

Coding at a Glance

Tabular directives: 4 Excludes1 · 3 code-also instructions
Risk adjustment: CMS-HCC V28: 1 category · CMS-HCC V22 category 40 · RxHCC V08 category 83

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 545 — CONNECTIVE TISSUE DISORDERS WITH MCC (MDC 08)
MS-DRG 546 — CONNECTIVE TISSUE DISORDERS WITH CC (MDC 08)
MS-DRG 547 — CONNECTIVE TISSUE DISORDERS WITHOUT CC/MCC (MDC 08)

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.

Risk Adjustment (CMS-HCC)

Payment categories this diagnosis maps to under CMS-HCC V28, payment year 2026.

HCC 93 — Rheumatoid Arthritis and Other Specified Inflammatory Rheumatic Disorders (supersedes HCC 94)

Other models: CMS-HCC V22 HCC 40 · RxHCC V08 HCC 83

Risk scores depend on the enrollee's full accepted diagnosis set and segment; a category mapping alone does not determine payment.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for M08.042 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 changes Change history Release, file and checksum

Notes without a marker are published on M08.042 itself; “inherited from” names the category or block whose note applies here.

Excludes1 — Not Coded Here

Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

arthropathy in Whipple's disease (M14.8) Compare M08.042 vs M14.8 →
Felty's syndrome (M05.0) Compare M08.042 vs M05.0 →
juvenile dermatomyositis (M33.0-) Compare M08.042 vs M33.0 →
psoriatic juvenile arthropathy (L40.54) Compare M08.042 vs L40.54 →

Source: inherited from M08

Code Also

Additional codes that may be required to fully describe the encounter.

any associated underlying condition, such as:
regional enteritis Crohn's disease
ulcerative colitis (K51.-) inherited from M08

Coder workflow for M08.042

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

Before you code M08.042

Unspecified does not mean incorrect. When the record gives no greater specificity, M08.042 may be the appropriate code. Check the record for detail that supports a more specific sibling. An unspecified code is for records that do not provide the detail a more specific code needs; a query, not an assumption, is the route to specificity (Guidelines I.A.9.b, I.B.18).
See the relationships section · Guide: Other vs unspecified (NEC vs NOS) →
Laterality is coded in this family. Confirm the side documented — right, left, or bilateral — and select the matching code (this page’s code: left). The unspecified-side code applies only when the record states no side. Laterality is assigned from the documented side; where a bilateral code exists and both sides are documented, it is used instead of two unilateral codes (Guidelines I.B.13).
ReviewM08.041 · right, M08.049 · unspecified
Guide: Laterality coding →
Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with M08.042. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).
See the official tabular notes

Choose the right path

Does the record document the detail a more specific sibling code needs?
Yes → Review the specific siblings in this subcategory.
No → Continue — M08.042 is appropriate when the documentation goes no further.
Does the documentation support a condition named in M08.042’s Excludes1 note?
Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
No → Continue.
ReviewM14.8, M05.0, M33.0, L40.54
Is the side documented?
Yes → Select the code for the documented side (or the bilateral code when both sides are documented and one exists).
No → Use the unspecified-side code only when the record states no side; a query is the alternative.
ReviewM08.041 · right, M08.049 · unspecified

Consider M08.042. Then review the Code Also note, and 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).
Laterality: Right, left or bilateral as documented; unspecified only when the record states no side (Guidelines I.B.13).
Any detail beyond this code’s title: What the record states that a more specific sibling code would capture — or its absence, which itself supports the unspecified code.

Official instructions as workflow

Excludes1 — check before selecting M08.042(4 notes)
Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with M08.042: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.
CompareM14.8, M05.0, M33.0, L40.54
See the official tabular notes · Guidelines I.A.12.a
Code Also — related condition(3 notes)
Coding workflow: Review the related condition when both are documented and the instruction applies. A Code Also note does not fix sequencing; the order follows the circumstances of the encounter.
ReviewK51
See the official tabular notes · Guidelines I.A.17

Coding decision scenarios

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

Documentation: The provider documents the condition in the terms of this code’s title and records no further detail.

Coding question: Is a more specific sibling code supportable?

Path: Review the subcategory for a sibling that names the missing detail.

Reason: A more specific code needs documentation of the distinguishing element; without it the unspecified code is appropriate, and a provider query is the route to specificity (Guidelines I.A.9.b, I.B.18).

Documentation: Both the condition M08.042 describes and a condition named in its Excludes1 note are documented for the same encounter.

Coding question: Can both codes be reported?

Path: Review the Excludes1 note and the excluded code, and look for a provider statement on whether the two conditions are related.

Reason: Excludes1 means the two are not coded together; the exception is when the record shows the conditions are unrelated to each other (Guidelines I.A.12.a).

ReviewM14.8, M05.0, M33.0, L40.54

Documentation: The record documents the condition on one side only.

Coding question: Which code in this family applies?

Path: Select the sibling code for the documented side.

Reason: Laterality is assigned from the documented side; the unspecified-side code is for records that state no side (Guidelines I.B.13).

ReviewM08.041 · right, M08.049 · unspecified

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 M08.042 with…

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

The codes most likely to be picked instead of M08.042 — 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.

M14.8— Excludes1 conflict (Excludes1 — generally not reported together)
Not coded here — the tabular list excludes this pair for the same encounter.
Not reported together with this code, except where the two conditions are documented as unrelated.
What moves you there: Documentation of arthropathy in Whipple's disease moves the case to M14.8; the two are not reported together unless documented as unrelated.
Full comparison: M08.042 vs M14.8 →
M05.0— Excludes1 conflict (Excludes1 — generally not reported together)
Not coded here — the tabular list excludes this pair for the same encounter.
Not reported together with this code, except where the two conditions are documented as unrelated.
What moves you there: Documentation of Felty's syndrome moves the case to M05.0; the two are not reported together unless documented as unrelated.
Full comparison: M08.042 vs M05.0 →
M33.0— Excludes1 conflict (Excludes1 — generally not reported together)
Not coded here — the tabular list excludes this pair for the same encounter.
Not reported together with this code, except where the two conditions are documented as unrelated.
What moves you there: Documentation of juvenile dermatomyositis moves the case to M33.0; the two are not reported together unless documented as unrelated.
Full comparison: M08.042 vs M33.0 →
L40.54— Excludes1 conflict (Excludes1 — generally not reported together)
Not coded here — the tabular list excludes this pair for the same encounter.
Not reported together with this code, except where the two conditions are documented as unrelated.
What moves you there: Documentation of psoriatic juvenile arthropathy moves the case to L40.54; the two are not reported together unless documented as unrelated.
Full comparison: M08.042 vs L40.54 →
M08.041— Laterality relationship (Review)
Same condition; these differ only in which side is documented.
The same condition on the other side; the documented side decides, and a bilateral code, where one exists, replaces the pair when both sides are documented.
What moves you there: A documented right side moves the case to M08.041.
Full comparison: M08.042 vs M08.041 →
M08.049— Laterality relationship (Review)
Same condition; these differ only in which side is documented.
The same condition on the other side; the documented side decides, and a bilateral code, where one exists, replaces the pair when both sides are documented.
What moves you there: A record that states no side takes M08.049; a documented side moves it back to a sided code.
Full comparison: M08.042 vs M08.049 →

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.

Code Overview

Unspecified juvenile rheumatoid arthritis, left hand is a billable ICD-10-CM diagnosis code (M08.042).

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

Decision Points

The directives on this code's own record, as a pre-claim checklist.

Laterality is coded in this family. Confirm the documented side matches the code — the opposite-side siblings are in the relationships section. See the opposite-side sibling codes
3 Code Also notes — a second code may apply; the guidelines leave its sequencing to the circumstances of the encounter. See the Code Also notes
4 Excludes1 entries — codes named there are generally not reported together with this code (Guidelines I.A.12.a). See the Excludes1 notes

Checklist rows are derived from this code's own official directives; the wording of each check is MedCoder editorial. The official notes themselves are in the sections each row links to.

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 M08.042 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 2 Excludes1 notes: M05 — Rheumatoid arthritis with rheumatoid factor (via M08.-), M08.9 — Juvenile arthritis, unspecified (via M08.0.-).

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

MS-DRG Grouper Relationships (FY2027)

Potential MS-DRG participation — not a DRG assignment.

FY2027 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 545 (MDC 08), DRG 546 (MDC 08), DRG 547 (MDC 08).

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

Clinical classification (AHRQ CCSR):MUS004 — Juvenile arthritis (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 condition, opposite side

Same category and title, differing only in which side of the body is affected.

M08.041 — Unspecified juvenile rheumatoid arthritis, right hand (right)Compare M08.042 vs M08.041 →, M08.049 — Unspecified juvenile rheumatoid arthritis, unspecified hand (unspecified)Compare M08.042 vs M08.049 →

Same CMS-HCC risk category (V28)

CMS maps these diagnoses to the same Hierarchical Condition Category (Rheumatoid Arthritis and Other Specified Inflammatory Rheumatic Disorders) for risk-adjusted payment.

Related risk categories

These categories interact through CMS's HCC hierarchy — one can suppress the other's risk-adjustment weight when both are present on a claim.

Systemic Lupus Erythematosus and Other Specified Systemic Connective Tissue Disorders

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Juvenile arthritis).

Same Index main term, other category

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

Contextual Map

Every relationship of M08.042 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 M08.042 with these 2 related codes in Claim Check

Hierarchy

M00-M99 — Chapter 13: Diseases of the Musculoskeletal System and Connective Tissue (M00-M99) (M00-M99)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
M00-M25 — Arthropathies[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
M05-M14 — Inflammatory polyarthropathies[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Referenced by Excludes1 notes

M05 — Rheumatoid arthritis with rheumatoid factor[Excludes1](via M08.-): “juvenile rheumatoid arthritis (M08.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
M08.9 — Juvenile arthritis, unspecified[Excludes1](via M08.0.-): “juvenile rheumatoid arthritis, unspecified (M08.0-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Clinical classification (CCSR)

MUS004 — Juvenile arthritis[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)

Risk adjustment (CMS-HCC)

HCC 93 — Rheumatoid Arthritis and Other Specified Inflammatory Rheumatic Disorders [CMS-HCC]: “Rheumatoid Arthritis and Other Specified Inflammatory Rheumatic Disorders — supersedes HCC 94 (Systemic Lupus Erythematosus and Other Specified Systemic Connective Tissue Disorders)”— CMS-HCC V28 · 2026

MS-DRG Grouper

DRG 545 — CONNECTIVE TISSUE DISORDERS WITH MCC[MS-DRG]: “CONNECTIVE TISSUE DISORDERS WITH MCC (MDC 08)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2027
DRG 546 — CONNECTIVE TISSUE DISORDERS WITH CC[MS-DRG]: “CONNECTIVE TISSUE DISORDERS WITH CC (MDC 08)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2027
DRG 547 — CONNECTIVE TISSUE DISORDERS WITHOUT CC/MCC[MS-DRG]: “CONNECTIVE TISSUE DISORDERS WITHOUT CC/MCC (MDC 08)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2027

MDC crossing

MDC 08 — Diseases and Disorders of the Musculoskeletal System and Connective Tissue[MDC crossing]: “Diseases and Disorders of the Musculoskeletal System and Connective Tissue — 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. 18,439 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2027

Nearest codes (40)

M08 — Juvenile arthritis[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
M08.0 — Unspecified juvenile rheumatoid arthritis[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
M08.00 — Unspecified juvenile rheumatoid arthritis of unspecified site[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
M08.01 — Unspecified juvenile rheumatoid arthritis, shoulder[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
M08.011 — Unspecified juvenile rheumatoid arthritis, right shoulder[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
M08.012 — Unspecified juvenile rheumatoid arthritis, left shoulder[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
M08.019 — Unspecified juvenile rheumatoid arthritis, unspecified shoulder[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
M08.02 — Unspecified juvenile rheumatoid arthritis of elbow[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
and 32 more

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 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
Risk adjustment Official source data: 2026 Mid-Year Final ICD-10 Mappings + Model Software (cms.gov/files/zip/2026-midyear-final-icd-10-mappings.zip, 2026-midyear-final-model-software.zip) — CMS-HCC V28, PY2026 mid-year final release 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. "M08.042 — Unspecified juvenile rheumatoid arthritis, left hand." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/m08.042-unspecified-juvenile-rheumatoid-arthritis-left-hand

Change history

FY2016 — October 1, 2015
In the code set at ICD-10-CM adoption
Unspecified juvenile rheumatoid arthritis, left hand

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 M08.042 in its code family, with their registry titles.

View all codes in the M08 family

M08.042 ICD-10-CM Code: Unspecified juvenile rheumatoid arthritis, left hand

Coding at a Glance

Inpatient Payment Groups (MS-DRG)

Risk Adjustment (CMS-HCC)

Coding instructions

Excludes1 — Not Coded Here

Code Also

Coder workflow for M08.042

Before you code M08.042

Choose the right path

Documentation check

Official instructions as workflow

Coding decision scenarios

Don’t confuse M08.042 with…

Code Overview

Decision Points

Verify Before Coding

Relationships & Classification

MS-DRG Grouper Relationships (FY2027)

Related Codes

Same condition, opposite side

Same CMS-HCC risk category (V28)

Related risk categories

Same clinical category (CCSR)

Same Index main term, other category

Contextual Map

Hierarchy

Referenced by Excludes1 notes

Clinical classification (CCSR)

Risk adjustment (CMS-HCC)

MS-DRG Grouper

MDC crossing

Nearest codes (40)

Change history

Sources for this page

Cite this page

Change history

Nearest Codes in This Family