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E11 ICD-10-CM Code: Type 2 diabetes mellitus

Billing Status: NO. This is a clinician non-billable / parent hierarchy grouping in the ICD-10-CM system.

Coding at a Glance

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for E11 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 changesChange historyRelease, file and checksum

Includes

Conditions the official ICD-10-CM tabular list includes under this code.

  • diabetes (mellitus) due to insulin secretory defect
  • diabetes NOS
  • insulin resistant diabetes (mellitus)

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).

Use Additional Code

Supplementary codes the tabular list directs you to add.

  • Use additional code to identify control using:
  • injectable non-insulin antidiabetic drugs (Z79.85)
  • insulin (Z79.4)
  • oral antidiabetic drugs (Z79.84)
  • oral hypoglycemic drugs (Z79.84)

Coder workflow for E11

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

Before you code E11

  1. E11 is not reportable as written. Select the more specific code beneath it that the documentation supports. Codes are reported to the highest level of specificity the classification provides (Guidelines I.B.2).

    ReviewE11.0, E11.1, E11.2, E11.3, E11.4, E11.5, E11.6, E11.8, E11.9, E11.A

    See the relationships section · Guide: How to choose an ICD-10-CM code →

  2. Confirm the documented diabetes type or cause (the E08–E13 categories are separated by it) and every documented complication or manifestation; the code is built from the type first and the complication second. Then work the category’s Use Additional Code notes for medication and control status. Type 2 is the default only when the type is not documented, and insulin or other medication use does not by itself establish the type (Guidelines I.C.4.a.2, I.C.4.a.3).

    Guide: Diabetes with multiple complications →

  3. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with E11. 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

  1. Does the documentation support one of the more specific codes beneath E11?
    Yes → Select that code and continue the checks below on its own page.
    No → E11 cannot be reported as written; query for the specificity its subcategory needs.

    ReviewE11.0, E11.1, E11.2, E11.3, E11.4, E11.5, E11.6, E11.8, E11.9, E11.A

  2. Does the documentation support a condition named in E11’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.

    ReviewE08, E09, O24.4, P70.2, E13, E10

Consider E11. Then work the Use Additional Code 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).
The conditions the Use Additional Code note names
Reported with this code when documented; a conditional instruction (“if applicable”, “if known”) applies only when the record supports it.
Diabetes type or cause, each complication, and medication use
The type is documented, not inferred from medication (Guidelines I.C.4.a.3); each documented complication takes its own combination code.

Official instructions as workflow

  • Excludes1 — check before selecting E11(8 notes)

    Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with E11: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

    CompareE08, E09, O24.4, P70.2, E13, E10

    See the official tabular notes · Guidelines I.A.12.a

  • Use Additional Code — after identifying E11(5 notes)

    Coding workflow: Check whether the documentation supports the additional code(s) the note names, and report them with E11 when it does. Where the instruction is conditional (“if applicable”, “if known”), it applies only when the record documents the condition.

    ReviewZ79.85, Z79.4, Z79.84

    See the official tabular notes · Guidelines I.A.13

Coding decision scenarios

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

Documentation: Both the condition E11 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).

ReviewE08, E09, O24.4, P70.2, E13, E10

Documentation: A condition the Use Additional Code note names is documented.

Coding question: Is a second code reported with E11?

Path: Review the Use Additional Code note and the code it names.

Reason: The additional code is reported when the record documents the condition; a conditional instruction applies only when its condition is met (Guidelines I.A.13).

ReviewZ79.85, Z79.4, Z79.84

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.

Code Overview

Type 2 diabetes mellitus is a non-billable ICD-10-CM category code (E11). A more specific billable subcode must be selected for claims submission.

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

Official Coding Guidelines

Official source data — quoted verbatim from the CMS/NCHS Official Guidelines

Official source data — quoted verbatim from the CMS/NCHS Official Guidelines

Verbatim excerpts from the ICD-10-CM Official Guidelines for Coding and Reporting (CMS/NCHS) that govern this code.

Chapter 4: Endocrine, Nutritional, and Metabolic Diseases (E00 -E89)

2) Type of diabetes mellitus not documented If the type of diabetes mellitus is not documented in the medical record the default is E11.-, Type 2 diabetes mellitus.

Chapter 4: Endocrine, Nutritional, and Metabolic Diseases (E00 -E89)

3) Diabetes mellitus and the use of insulin, oral hypoglycemics, and injectable non-insulin drugs If the documentation in a medical record does not indicate the type of diabetes but does indicate that the patient uses insulin, code E11-, Type 2 diabetes mellitus, should be assigned. Additional code(s) should be assigned from category Z79 to identify the long-term (current) use of insulin, oral hypoglycemic drugs, or injectable non-insulin antidiabetic, as follows: If the patient is treated with both oral hypoglycemic drugs and insulin, both code Z79.4, Long term (current) use of insulin, and code Z79.84, Long term (current) use of oral hypoglycemic drugs, should be assigned. If the patient is treated with both insulin and an injectable non-insulin antidiabetic drug, assign codes Z79.4, Long term (current) use of insulin, and Z79.85, Long-term (current) use of injectable non-insulin antidiabetic drugs. If the patient is treated with both oral hypoglycemic drugs and an injectable non-insulin antidiabetic drug, assign codes Z79.84, Long term (current) use of oral hypoglycemic drugs, and Z79.85, Long-term (current) use of injectable non-insulin antidiabetic drugs. Code Z79.4 should not be assigned if insulin is given temporarily to bring a type 2 patient’s blood sugar under control during an encounter.

Verify Before Coding

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 E11 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 21 Excludes1 notes across 8 chapters: E08 — Diabetes mellitus due to underlying condition, E09 — Drug or chemical induced diabetes mellitus, E10 — Type 1 diabetes mellitus, E74 — Other disorders of carbohydrate metabolism, G54.5 — Neuralgic amyotrophy, G59 — Mononeuropathy in diseases classified elsewhere, G63 — Polyneuropathy in diseases classified elsewhere, G99.0 — Autonomic neuropathy in diseases classified elsewhere, H20.0 — Acute and subacute iridocyclitis, I73.8 — Other specified peripheral vascular diseases, I79.8 — Other disorders of arteries, arterioles and capillaries in diseases classified elsewhere, L92.1 — Necrobiosis lipoidica, not elsewhere classified, L99 — Other disorders of skin and subcutaneous tissue in diseases classified elsewhere, M14 — Arthropathies in other diseases classified elsewhere, M14.6 — Charcôt's joint, M90 — Osteopathies in diseases classified elsewhere, N08 — Glomerular disorders in diseases classified elsewhere, N16 — Renal tubulo-interstitial disorders in diseases classified elsewhere, N76.82 — Fournier disease of vagina and vulva, R40 — Somnolence, stupor and coma, +1 more.

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

Referenced by 3 Excludes2 notes across 3 chapters: E87.0 — Hyperosmolality and hypernatremia, H35 — Other retinal disorders, I96 — Gangrene, not elsewhere classified.

These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.

Referenced by 1 Code First instruction: D84.81 — Immunodeficiency due to conditions classified elsewhere.

Each of these codes carries a Code First note naming this condition — when that code is reported, THIS code is sequenced first, ahead of it.

Referenced by 1 Code Also instruction: N76.82 — Fournier disease of vagina and vulva.

These codes suggest coding this condition alongside when both are present.

Contextual Map

Every relationship of E11 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 E11 with these 19 related codes in Claim Check

Hierarchy

Excludes1

Use Additional Code

Referenced by Excludes1 notes (21)

Referenced by Excludes2 notes

  • E87.0 — Hyperosmolality and hypernatremia[Excludes2]: “diabetes with hyperosmolarity (E08, E09, E11, E13 with final characters .00 or .01)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
  • H35 — Other retinal disorders[Excludes2]: “diabetic retinal disorders (E08.311-E08.359, E09.311-E09.359, E10.311-E10.359, E11.311-E11.359, E13.311-E13.359)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
  • I96 — Gangrene, not elsewhere classified[Excludes2]: “gangrene in diabetes mellitus (E08-E13 with .52)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Code First instructions

Referenced by Code Also instructions

Nearest codes (116)

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Common coding questions

Can E11 be billed directly?

No. E11 (Type 2 diabetes mellitus) is a non-billable ICD-10-CM category code. A more specific billable subcode must be selected based on clinical documentation.

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
Coding guidelines Official source data
ICD-10-CM Official Guidelines for Coding and Reporting (FY2027), quoted by section 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
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. "E11 — Type 2 diabetes mellitus." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/e11-type-2-diabetes-mellitus

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Type 2 diabetes mellitus

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 E11 in its code family, with their registry titles.