E13
Non-Billable (Header)Other specified diabetes mellitus
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
What This Code Means
E13 is the ICD-10-CM diagnosis code for other specified diabetes mellitus. E13 sits in the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89), within the section covering diabetes mellitus (e08-e13).
Header codes like E13 cannot be reported on claims directly — they organize child codes that share clinical context but the actual diagnosis must be coded to the highest level of specificity supported by the documentation. Coders should look at E13's child codes and select the one that matches the patient's documented presentation, since payers reject header codes submitted as the primary diagnosis. For risk adjustment workflows, header codes never contribute to a Medicare Advantage member's RAF score on their own; only billable child codes that happen to map to a payment HCC affect risk-adjusted plan payments.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for E13 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Includes
- diabetes mellitus due to genetic defects of beta-cell function
- diabetes mellitus due to genetic defects in insulin action
- postpancreatectomy diabetes mellitus
- postprocedural diabetes mellitus
- secondary diabetes mellitus NEC
Excludes 1 — Do NOT code together
- diabetes (mellitus) due to autoimmune process (E10.-)
- diabetes (mellitus) due to immune mediated pancreatic islet beta-cell destruction (E10.-)
- diabetes mellitus due to underlying condition (E08.-)
- drug or chemical induced diabetes mellitus (E09.-)
- gestational diabetes (O24.4-)
- neonatal diabetes mellitus (P70.2)
- type 1 diabetes mellitus (E10.-)