E08 vs R40.2423
E08 (Diabetes mellitus due to underlying condition) compared with R40.2423 (Glasgow coma scale score 9-12, at hospital admission), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. R40.2423 carries an Excludes1 note covering E08: “somnolence, stupor and coma in diabetes (E08-E13)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Side by side
| E08Diabetes mellitus due to underlying condition | R40.2423Glasgow coma scale score 9-12, at hospital admission | |
|---|---|---|
| Billing status | Non-billable header | Billable |
| Classification | E00-E89 — Endocrine, Nutritional and Metabolic Diseases (E00-E89) | R00-R99 — Symptoms, Signs and Abnormal Clinical and Laboratory Findings, Not Elsewhere Classified (R00-R99) |
| Definition | Diabetes mellitus due to underlying condition is a non-billable ICD-10-CM category code (E08). | Glasgow coma scale score 9-12, at hospital admission is a billable ICD-10-CM diagnosis code (R40.2423). |
| 7th character | — | The following appropriate 7th character is to be added to subcategory R40.24-: |
| Use additional code | code to identify control using: injectable non-insulin antidiabetic drugs (Z79.85) insulin (Z79.4) | — |
| Code first | the underlying condition, such as: congenital rubella (P35.0) | any associated: fracture of skull (S02.-) |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources