M1A.03 vs M1A.0310
M1A.03 (Idiopathic chronic gout, wrist) compared with M1A.0310 (Idiopathic chronic gout, right wrist, without tophus (tophi)), from the official CMS tabular data.
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
Summary
These codes represent different levels of the same hierarchy: M1A.03 is the non-billable header that contains M1A.0310, so only M1A.0310 (or a sibling) is reported.
Registry fact- What is different?
Title wording and billing status.The titles share “Idiopathic chronic gout”; M1A.03 says “wrist” where M1A.0310 says “right wrist, without tophus (tophi)”. M1A.03 is a non-billable header; M1A.0310 is billable.
Registry fact
- Can these codes be reported together?
Not as a pair.M1A.03 is the non-billable header that contains M1A.0310. A header is not reported on a claim, so the choice is M1A.0310 or a sibling that matches the documentation.
Registry fact
- Is there an Excludes1 relationship?
None.Neither entry carries an Excludes1 note that names the other code. M1A.03 carries 1 Excludes1 note and M1A.0310 carries 1 Excludes1 note covering other codes; the side-by-side table quotes them.
Official rule
- Is there an Excludes2 relationship?
None.Neither entry carries an Excludes2 note that names the other code. M1A.03 carries 1 Excludes2 note and M1A.0310 carries 1 Excludes2 note covering other codes; the side-by-side table quotes them.
Official rule
- Is one more specific?
Yes.M1A.0310 is a subdivision of M1A.03 in the tabular hierarchy, so it is the more specific of the two.
Registry fact
- Is one a parent or header code?
Yes.M1A.03 is the non-billable header that contains M1A.0310. A header stands for the whole family beneath it and is not reported on a claim.
Registry fact
- Are there sequencing instructions?
None.Neither entry carries a Code First or Use Additional Code note that names the other.
Official rule
- Are there other coding relationships?
None found.No laterality, encounter-phase, Table of Neoplasms, Table of Drugs and Chemicals, or history-versus-active-disease relationship links these codes.
MedCoder-derived
Official rule: a tabular instructional note or a section of the ICD-10-CM Official Guidelines, quoted as published. Registry fact: the codes’ own published attributes (titles, billable status, position in the hierarchy, code set). MedCoder-derived: a reading MedCoder computes from those facts; it is not itself a rule. How to read the labels
Can these codes be reported together?
Not as a pair — M1A.03 is not reportable. M1A.03 is the non-billable category that contains M1A.0310.
A header stands for the whole family of codes beneath it and is not reported on a claim, so the choice is M1A.0310 or a sibling that matches the documentation. No Excludes1/Excludes2 relationship exists between these codes in the official tabular list.
Official guidance behind these answers
Section I.B.2 — Level of Detail in Coding · applies to: M1A.03 and M1A.0310
Diagnosis codes are to be used and reported at their highest number of characters available and to the highest level of specificity documented in the medical record. ICD-10-CM diagnosis codes are composed of codes with 3, 4, 5, 6 or 7 characters. Codes with three characters are included in ICD-10-CM as the heading of a category of codes that may be further subdivided by the use of fourth and/or fifth characters and/or sixth characters, which provide greater detail. A three-character code is to be used only if it is not further subdivided. A code is invalid if it has not been coded to the full number of characters required for that code, including the 7th character, if applicable.
ICD-10-CM Official Guidelines FY2027
Quoted from the ICD-10-CM Official Guidelines for Coding and Reporting in effect for the release shown. The tabular notes above are the code-level instruction; these sections are the convention that says how such a note is applied. Source document (CMS PDF) · Release and checksum
Side by side
| M1A.03Idiopathic chronic gout, wrist | M1A.0310Idiopathic chronic gout, right wrist, without tophus (tophi) | |
|---|---|---|
| Billing status | Non-billable header Report instead: M1A.0310, M1A.0311, M1A.0320, M1A.0321, M1A.0390 | Billable |
| Classification | M00-M99 — Diseases of the Musculoskeletal System and Connective Tissue (M00-M99) | M00-M99 — Diseases of the Musculoskeletal System and Connective Tissue (M00-M99) |
| Definition | Idiopathic chronic gout, wrist is a non-billable ICD-10-CM category code (M1A.03). | Idiopathic chronic gout, right wrist, without tophus (tophi) is a billable ICD-10-CM diagnosis code (M1A.0310). |
| 7th character | The appropriate 7th character is to be added to each code from category M1A | The appropriate 7th character is to be added to each code from category M1A |
| Excludes1 | gout NOS (M10.-) | gout NOS (M10.-) |
| Excludes2 | acute gout (M10.-) | acute gout (M10.-) |
| Use additional code | code to identify: Autonomic neuropathy in diseases classified elsewhere (G99.0) Calculus of urinary tract in diseases classified elsewhere (N22) | code to identify: Autonomic neuropathy in diseases classified elsewhere (G99.0) Calculus of urinary tract in diseases classified elsewhere (N22) |
Notes are the code’s own tabular entry, quoted as published. A note that names the other code is the one the verdict above rests on.
Derived from the official CMS ICD-10-CM tabular data (FY2027). A coding-rule comparison, not billing advice: payer-specific edits and medical-necessity policy are outside its scope. All data sources