M1A vs M1A.00X0
M1A (Chronic gout) compared with M1A.00X0 (Idiopathic chronic gout, unspecified site, without tophus (tophi)), from the official CMS tabular data.
Summary
These codes represent different levels of the same hierarchy: M1A is the non-billable header that contains M1A.00X0, so only M1A.00X0 (or a sibling) is reported.
Registry fact- What is different?
The conditions named and billing status.M1A is “Chronic gout”; M1A.00X0 is “Idiopathic chronic gout, unspecified site, without tophus (tophi)”. M1A is a non-billable header; M1A.00X0 is billable.
Registry fact
- Can these codes be reported together?
Not as a pair.M1A is the non-billable header that contains M1A.00X0. A header is not reported on a claim, so the choice is M1A.00X0 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 carries 1 Excludes1 note and M1A.00X0 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 carries 1 Excludes2 note and M1A.00X0 carries 1 Excludes2 note covering other codes; the side-by-side table quotes them.
Official rule
- Is one more specific?
Yes.M1A.00X0 is a subdivision of M1A in the tabular hierarchy, so it is the more specific of the two.
Registry fact
- Is one a parent or header code?
Yes.M1A is the non-billable header that contains M1A.00X0. 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 is not reportable. M1A is the non-billable category that contains M1A.00X0.
A header stands for the whole family of codes beneath it and is not reported on a claim, so the choice is M1A.00X0 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 and M1A.00X0
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 FY2026
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
| M1AChronic gout | M1A.00X0Idiopathic chronic gout, unspecified site, without tophus (tophi) | |
|---|---|---|
| Billing status | Non-billable header Report instead: M1A.00X0, M1A.00X1, M1A.0110, M1A.0111, M1A.0120 | 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 | Chronic gout is a non-billable ICD-10-CM category code (M1A). | Idiopathic chronic gout, unspecified site, without tophus (tophi) is a billable ICD-10-CM diagnosis code (M1A.00X0). |
| 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