ICD-10 Code for Diabetes Type 2 (E11) – Complete Guide with Complications & Combinations
SEQUENCE / OUTLINE
- ICD-10 Code E11 For type 2 Diabetes Mellitus
- E11.65 – Type 2 Diabetes Mellitus With Hyperglycemia
- E11.2 Series – Diabetes With Kidney Complications
- E11.3 Series – Diabetes With Ophthalmic Complications
- E11.4 Series – Diabetes With Neurological Complications
- E11.5 Series – Diabetes With Circulatory Complications
- E11.6 Series – Skin & Ulcer Complications
- E11.8 – Type 2 Diabetes Mellitus With Unspecified Complications
- E11.9 – Type 2 Diabetes Without Complications (Extended Clarification)
- ICD-10 Combination Coding For Type 2 Diabetes
- Z79.4 & Z79.84 – Long-term Medication Use With Diabetes
- Pediatric Coding for type 2 Diabetes (E11 Series)
- Conclusion
- FAQs
ICD-10 Code E11 for Type 2 Diabetes Mellitus
Type 2 diabetes mellitus is coded under the E11 category in ICD-10-CM. This category includes all documented cases where the patient has Type 2 diabetes, regardless of whether the condition is diet-controlled, treated with oral medications, or requires long-term insulin. The base code E11 is rarely used alone. In most clinical notes, diabetes is linked to a complication or additional condition, so a more specific code from the E11.x series is required. If no complications are documented, only then should an uncomplicated E11.9 code be used. Coders should verify three things in the provider’s note before selecting a code:
Is a complication documented?
(e.g., neuropathy, CKD, retinopathy, foot ulcers)Is the diabetes controlled, poorly controlled, or associated with hyperglycemia?
Is the patient on long-term insulin or oral hypoglycemics?
(Z79.4 or Z79.84 may be required)
E11.9 – Type 2 Diabetes Mellitus Without Complications
E11.9 is used when the provider confirms a diagnosis of Type 2 diabetes mellitus without any documented complications. This means the chart does not mention kidney disease, nerve damage, eye findings, ulcers, circulatory disorders, or hyperglycemia. E11.9 is also used when the documentation is:
General (e.g., “Type 2 diabetes, stable”)
Ambiguous (no complications mentioned)
Focused solely on routine management or medication follow-up
If the documentation is unclear, coding guidelines instruct coders to default to Type 2 diabetes, meaning E11.9 is the correct assignment unless the provider specifies otherwise. Even with uncomplicated diabetes, coders may still need to add additional codes for:
Long-term insulin use (Z79.4)
Long-term oral antidiabetic use (Z79.84)
Dietary management (Z71.3, if applicable)
E11.65 – Type 2 Diabetes Mellitus With Hyperglycemia
E11.65 is assigned when the provider documents Type 2 diabetes with hyperglycemia, meaning the patient’s blood glucose levels are higher than the expected range. This code is used whether the condition is described as:
Poorly controlled
Uncontrolled
Hyperglycemic
Experiencing elevated glucose readings
Experiencing worsening glycemic control
In ICD-10-CM, terms like “poorly controlled” or “uncontrolled” Type 2 diabetes are interpreted as hyperglycemia, and E11.65 is the appropriate code unless another specific complication is also documented.
When to Use E11.65
E11.65 applies when:
Blood glucose documentation shows persistent or significant elevation
The provider notes “poor glycemic control”
The patient is experiencing steroid-induced glucose spikes (if linked to diabetes)
A treatment change is made due to elevated sugars
What NOT to code as E11.65
Do not assign E11.65 when:
Documentation shows hypoglycemia (use E11.64 series)
The patient is stable and at goal (use E11.9 unless complications exist)
Elevated readings are mentioned without clinical significance or diagnosis
Related Codes to Consider
If the provider also documents long-term medication use, coders may need additional Z-codes, such as:
Z79.4 – Long-term use of insulin
Z79.84 – Long-term use of oral antidiabetic medications
These secondary codes explain ongoing management but do not replace E11.65.
E11.2 Series – Diabetes with Kidney Complications
E11.21 – Type 2 Diabetes Mellitus With Diabetic Nephropathy
E11.21 is assigned when the provider documents diabetic nephropathy, meaning kidney damage directly linked to diabetes. This code is used when notes include language such as:
Diabetic nephropathy
Diabetic kidney damage
Diabetic renal disease
Diabetic proteinuria or albuminuria
Key Coding Points:
No secondary CKD code is required unless the provider documents an actual CKD stage.
If the note only states “nephropathy” but doesn’t specify diabetic origin, query the provider for clarification.
If the provider confirms it is “diabetic nephropathy,” E11.21 is the correct code.
E11.22 – Type 2 Diabetes Mellitus With Chronic Kidney Disease (CKD)
Use E11.22 when the provider documents CKD caused by or associated with Type 2 diabetes. This requires two codes:
E11.22 – Diabetes with CKD
N18.x – CKD stage
N18.1–N18.9 (Stage 1–5 or unspecified)
N18.6 for ESRD
Important Documentation Notes
The provider must specify both “diabetes” and “CKD” or state a relationship (“diabetic CKD,” “diabetes with CKD,” etc.).
If the stage is not documented, use N18.9 (CKD unspecified).
If ESRD is present, assign N18.6.
Example
“Type 2 diabetes with CKD stage 3” → E11.22 + N18.3
Related Reading: Nationwide Nephrology Billing Services
E11.29 – Type 2 Diabetes Mellitus With Other Kidney Complications
E11.29 is used when:
Kidney involvement is documented
The condition is related to diabetes
But it does not fall under nephropathy or CKD staging
Examples may include:
Diabetic renal disorder, unspecified
Early kidney changes related to diabetes
Renal complications not clearly defined as CKD or nephropathy
If the documentation is vague, coders should ensure clarification from the provider.
E11.3 Series – Diabetes with Ophthalmic Complications
E11.31 – Type 2 Diabetes Mellitus With Unspecified Diabetic Retinopathy
Use E11.31 when the provider documents diabetic retinopathy but does not specify:
Type
Laterality (right, left, bilateral)
Whether macular edema is present
Examples of documentation that map to E11.31:
“Diabetic retinopathy”
“Retinopathy due to diabetes”
“Changes consistent with diabetic eye disease”
If the provider mentions macular edema or specifies the severity (mild, moderate, severe), a more specific code from the E11.32–E11.39 range is required.
E11.319 – Type 2 Diabetes Mellitus With Unspecified Retinopathy, Without Macular Edema
Assign E11.319 when documentation states:
Diabetic retinopathy (type unspecified)
Without mention of macular edema
No severity or laterality indicated
This is one of the most common codes used in ophthalmology reports when retinopathy is noted but details are minimal.
Examples:
“NPDR without macular edema” (if severity is unspecified)
“Retinopathy related to diabetes, no edema seen”
Other Retinopathy Codes in the E11.3 Series
The E11.3 range includes more specific classifications depending on severity and presence of macular edema. These are used when documentation includes:
Mild nonproliferative diabetic retinopathy
Moderate NPDR
Severe NPDR
Proliferative diabetic retinopathy
Presence or absence of macular edema
Laterality (right, left, bilateral)
Coders should assign the most specific code supported by the record. If any key details are missing, providers may need clarification
E11.4 Series – Diabetes with Neurological Complications
E11.40 – Type 2 Diabetes Mellitus With Diabetic Neuropathy, Unspecified
Use E11.40 when documentation indicates neuropathy caused by diabetes, but does not clarify the type. This includes common phrases such as:
“Diabetic neuropathy”
“Neuropathy secondary to diabetes”
“Nerve damage due to diabetes”
If the provider does not specify whether it is mononeuropathy, polyneuropathy, or autonomic neuropathy, E11.40 is the correct choice
E11.41 – Type 2 Diabetes Mellitus With Diabetic Mononeuropathy
Assign E11.41 when the record documents mononeuropathy associated with diabetes. Examples include:
Single nerve involvement
Diabetic cranial nerve palsy
Diabetic median or ulnar nerve mononeuropathy
This code reflects localized nerve involvement rather than systemic.
E11.42 – Type 2 Diabetes Mellitus With Diabetic Polyneuropathy
E11.42 is one of the most commonly used neuropathy codes, and your Queries.csv confirms high search interest in it. Use this code when documentation includes:
“Diabetic polyneuropathy”
“Peripheral neuropathy due to diabetes”
“Length-dependent neuropathy in diabetes”
“Bilateral foot neuropathy due to diabetes”
Because polyneuropathy is the most frequent neurological manifestation in diabetes, this code appears often in outpatient and podiatry notes
E11.43 – Type 2 Diabetes Mellitus With Diabetic Autonomic Neuropathy
Use E11.43 when autonomic involvement is clearly documented. Examples include:
Orthostatic hypotension due to diabetes
Gastroparesis of diabetic origin
Diabetic bladder dysfunction
Autonomic neuropathy symptoms linked to diabetes
Autonomic manifestations are less common but still important to code accurately
E11.5 Series – Diabetes with Circulatory Complications
E11.51 – Type 2 Diabetes Mellitus With Diabetic Peripheral Angiopathy
Use E11.51 when the provider documents:
Peripheral angiopathy due to diabetes
PAD/PVD associated with diabetes
Vascular insufficiency caused by diabetes
Lower-extremity arterial narrowing linked to diabetes
Common documentation examples include:
“Diabetic peripheral arterial disease”
“Ischemic changes in feet due to diabetes”
“Peripheral angiopathy in diabetic patient”
If the provider also documents rest pain, ulcers, or gangrene, additional codes are required
E11.52 – Type 2 Diabetes Mellitus With Gangrene
Assign E11.52 when gangrene is documented as a complication of diabetes. Gangrene reflects advanced vascular compromise and usually requires immediate attention. Documentation that supports E11.52 includes:
“Gangrene of foot due to diabetes”
“Ischemic gangrene in diabetic patient”
“Dry or wet gangrene related to diabetes”
Additional Coding Guidance
If a specific site of gangrene is noted, assign a site-specific code (e.g., I96).
Ulcers associated with gangrene require L97.x in addition to E11.52.
If PAD is documented along with gangrene, both conditions should be coded.
E11.59 – Type 2 Diabetes Mellitus With Other Circulatory Complications
Use E11.59 when circulatory involvement is documented but does not clearly fall under peripheral angiopathy or gangrene. Examples:
Early vascular changes in diabetes
Impaired circulation not otherwise specified
Microangiopathy due to diabetes
This is a good “catch-all” category for vascular issues that are linked to diabetes but lack specific classification.
Coding Tips for Circulatory Complications
If PAD or gangrene is due to another condition (e.g., smoking-related PAD), the relationship must be documented before assigning E11.51 or E11.52.
Use Combination Coding When Required
Common combinations from real GSC queries:
E11.51 + I73.9 — Diabetes with PAD
E11.52 + I96 — Diabetes with gangrene
E11.51 + L97.x — Diabetes with foot ulcer and PAD
Watch for Laterality
If the ulcer or ischemia is on a specific foot or leg, always include the correct laterality code in the L97.x series
E11.6 Series – Skin & Ulcer Complications
E11.621 – Type 2 Diabetes Mellitus With Foot Ulcer
Use E11.621 when the provider documents a foot ulcer caused by or associated with diabetes.
Common documentation examples:
“Diabetic foot ulcer”
“Ulcer of left foot due to diabetes”
“Non-healing diabetic foot wound”
“Neuropathic ulcer in diabetic patient”
Required Combination Coding
E11.621 must be paired with an L97.x code to specify:
Ulcer location
Depth
Laterality
Severity
Examples:
L97.421 – Ulcer of left heel and midfoot with necrosis of bone
L97.511 – Ulcer of right ankle with breakdown of skin
Without the L97.x code, the documentation is incomplete.
Related Service: Our support for Wound Care Billing, Coding and documentation
E11.622 – Type 2 Diabetes Mellitus With Other Skin Ulcers
Assign E11.622 when the provider documents a skin ulcer caused by diabetes not located on the foot. Examples:
Diabetic ulcer of the calf
Ulcer on thigh associated with diabetes
Non-pressure leg ulcer in diabetic patient
Just like with E11.621, an accompanying L97.x code is required to capture the ulcer’s specifics.
E11.628 – Type 2 Diabetes Mellitus With Other Skin Complications
Use E11.628 for skin complications related to diabetes that are not ulcers, such as:
Diabetic dermatitis
Skin infections associated with diabetes
Diabetic bullae
Necrobiosis lipoidica (when linked to diabetes)
This is a broad category used when the provider clearly links the skin condition to the diabetes but it does not meet the criteria for an ulcer or necrosis.
E11.69 – Type 2 Diabetes Mellitus With Other Specified Complications
E11.69 is assigned when a documented complication is clearly related to diabetes but doesn’t fit into kidney, eye, neurological, circulatory, or skin categories. Examples:
Gastrointestinal complications associated with diabetes
Diabetic arthropathy (if documented as related)
Other specified systemic effects
This code should not be used as a fallback for unspecified complications—only when the complication is clearly defined but does not fit into another E11.x range
Coding Tips for Skin & Ulcer Complications
1. Always capture the full picture
Diabetes + ulcer always requires:
The E11.621 or E11.622 code
A corresponding L97.x code detailing severity and site
2. Neuropathy or PAD may also need to be coded
If the documentation includes neuropathy or peripheral angiopathy, those conditions must be reported separately.
3. Distinguish pressure vs non-pressure ulcers
If a pressure ulcer is documented, use L89.x codes.
If not, use L97.x (non-pressure).
4. Clarify laterality when needed
If the note does not specify left/right location, query the provider for clarification to ensure accurate coding.
E11.8 – Type 2 Diabetes Mellitus With Unspecified Complications
Use E11.8 when the provider documents that the patient has a complication of diabetes, but the specific type of complication is not clearly described. Examples of documentation that may require E11.8:
“Diabetes with complications” (no details provided)
“Diabetic complications – unspecified”
“Diabetes with systemic involvement”
Important Notes
E11.8 should never be used when a specific complication is documented elsewhere in the note.
If the complication is identifiable (e.g., neuropathy, CKD, ulceration), use the appropriate specific code instead.
When the documentation is unclear, consider requesting clarification from the provider.
This code is useful, but should be used conservatively to avoid over-generalization
E11.9 – Type 2 Diabetes Mellitus Without Complications (Extended Clarification)
E11.9 is used when:
No complications are documented
Provider notes “controlled,” “stable,” or “well-managed” diabetes
The visit is for routine follow-up or medication review
There is no evidence of end-organ involvement
Additional ICD-10 Codes That May Be Required
Even in uncomplicated diabetes, the following may apply:
Z79.4 – Long-term insulin use
Z79.84 – Long-term use of oral hypoglycemic agents
Z71.3 – Dietary management counseling (if applicable)
When to Use E11.8 vs. E11.9
| Code | When to Use | Documentation Example |
|---|---|---|
| E11.8 | A complication exists, but it is unspecified | “Diabetes with complications,” no further detail |
| E11.9 | No complications are documented | “Type 2 diabetes, well controlled” |
| Correctly distinguishing between these two codes ensures accurate coding and aligns with provider intent. | ||
ICD-10 Combination Coding for Type 2 Diabetes
ICD-10-CM requires coders to report both the diabetes code and the related secondary code when the complication involves:
Chronic kidney disease
Ulcers
Gangrene
Peripheral artery disease
Vision loss
Medication use
Pressure vs non-pressure ulcers
These combinations provide the clinical detail needed to reflect severity, site, and progression of the disease.
🔹 1. Diabetes With Chronic Kidney Disease (E11.22 + N18.x)
Use this combination when the provider documents CKD caused by or associated with diabetes.
Primary Code:
- E11.22 – Type 2 diabetes with CKD
Add a Secondary Code for CKD Stage:
- N18.1–N18.5 for stages 1–5
- N18.6 for end-stage renal disease
- N18.9 for CKD, unspecified
Example Documentation → Coding
- “Type 2 diabetes with CKD stage 3”
→ E11.22 + N18.3 - “Diabetes with ESRD on dialysis”
→ E11.22 + N18.6
→ Add dialysis codes if documented
🔹 2. Diabetes With Foot Ulcer (E11.621 + L97.x)
When a foot ulcer is due to diabetes:
Primary Code:
E11.621 – Diabetes with foot ulcer
Secondary Code (Required):
Use an L97.x code to indicate:
Site (ankle, heel, midfoot, toes)
Laterality (left, right)
Depth (skin breakdown, fat layer exposed, necrosis, bone involvement)
Example
“Ulcer of left heel due to diabetes, necrosis of bone”
→ E11.621 + L97.423
🔹 3. Diabetes With Gangrene (E11.52 + I96)
Use this combination when gangrene is documented as a diabetes-related complication.
Primary Code:
E11.52 – Diabetes with gangrene
Additional Secondary Code:
I96 – Gangrene, not elsewhere classified
Example
“Gangrene of right forefoot due to diabetes”
→ E11.52 + I96
→ Add ulcer codes if present
→ Add PAD codes if documented (I73.x)
🔹 4. Diabetes With Peripheral Artery Disease (E11.51 + I73.x)
When PAD or PVD is documented as related to diabetes:
Primary Code:
E11.51 – Diabetes with peripheral angiopathy
Secondary Code:
I73.9 – Peripheral vascular disease, unspecified
(or a more specific I73.x code if documented)
Example
“Type 2 diabetes with PAD”
→ E11.51 + I73.9
🔹 5. Diabetes With Vision Loss (E11.3x + H54.x)
When diabetic retinopathy leads to visual impairment:
Primary Code
Appropriate E11.3x retinopathy code
Secondary Code
H54.x – Level of visual impairment
Example
“Severe NPDR in left eye with vision loss”
→ E11.339 + H54.62
🔹 6. Long-Term Insulin Use (Z79.4) & Oral Medication Use (Z79.84)
These secondary codes do not replace the E11 code—they are added when medications are part of ongoing diabetes management.
Use Z79.4 when:
The patient is on long-term insulin therapy
The provider notes “insulin dependent” or “long-term insulin use”
Use Z79.84 when:
The patient uses long-term oral hypoglycemics
The patient is on metformin, sulfonylureas, SGLT2 inhibitors, etc.
Examples
“Type 2 diabetes on long-term insulin”
→ E11.x + Z79.4“Type 2 diabetes managed with metformin only”
→ E11.x + Z79.84
🔹 7. Diabetes With Pressure Ulcers (E11.x + L89.x)
If the ulcer is a pressure ulcer, not a diabetic neuropathic ulcer:
Use the appropriate E11.x code based on diabetes status
Add the L89.x code to specify staging and location
This distinction matters because many coders incorrectly use L97.x for pressure ulcers.
Z79.4 and Z79.84 – Long-term Medication Use with Diabetes
This section clarifies when to add the appropriate Z-codes and how they interact with E11-series codes.
Z79.4 – Long-Term (Current) Use of Insulin
Use Z79.4 when the provider documents that the patient is on long-term or chronic insulin therapy. Typical documentation supporting Z79.4 includes:
“Patient on long-term insulin”
“Insulin dependent” (for Type 2 patients only)
“Insulin therapy for ongoing management”
“Basal insulin + mealtime insulin regimen”
Important Clarifications
Z79.4 does not replace the E11 code.
It is added to show the medication component of the treatment plan.
If the patient is using insulin temporarily (e.g., for short-term inpatient management), do not assign Z79.4.
Examples
“Type 2 diabetes on long-term insulin therapy”
→ E11.x + Z79.4
Z79.84 – Long-Term Use of Oral Antidiabetic Medications
Use Z79.84 when documentation shows that the patient is taking ongoing oral diabetes medications, such as:
Metformin
Sulfonylureas
DPP-4 inhibitors
SGLT2 inhibitors
Thiazolidinediones
GLP-1 receptor agonists (if oral formulation)
When to Use Z79.84
Z79.84 applies when:
The patient uses oral medication as part of long-term management
Medication refills, adjustments, or follow-ups are documented
The provider indicates continued pharmacologic therapy
Example
“T2DM managed with metformin”
→ E11.x + Z79.84
Using Both Codes Together: Z79.4 + Z79.84
When a patient uses both insulin and oral medications, assign both codes:
Z79.4 – Long-term insulin
Z79.84 – Long-term oral medications
Example
“Type 2 diabetes treated with metformin and long-term insulin”
→ E11.x + Z79.4 + Z79.84
Do Not Use Z79.4 for Type 1 Diabetes
Although type 1 patients rely on insulin, Z79.4 is not assigned with Type 1 diabetes. Their insulin use is considered inherent to the condition and does not require a separate Z-code.
Pediatric Coding for Type 2 Diabetes (E11 Series)
Coding Type 2 Diabetes in Children Using the E11 Series
In ICD-10-CM, children with Type 2 diabetes are still coded using the same E11.x series codes as adults. There is no separate pediatric category—the code depends solely on the complication documented, not the patient’s age.
When a child has no complications
Assign E11.9 when Type 2 diabetes is documented without any associated conditions:
“Child with Type 2 diabetes, stable”
“Adolescent with new-onset T2DM, no complications”
When complications exist
If complications such as nephropathy, hyperglycemia, retinopathy, or neuropathy are present, select the appropriate subcode from the E11 series. Examples:
E11.65 – With hyperglycemia
E11.21 – With diabetic nephropathy
E11.40 – With neuropathy
E11.31 – With retinopathy
The coding rules remain exactly the same as for adults.
Medication Use Codes in Children
If a child with Type 2 diabetes is taking insulin or oral medications long-term, assign the appropriate Z-codes:
Z79.4 – Long-term insulin use
Z79.84 – Long-term oral antidiabetic medications
These codes apply regardless of the patient’s age, as long as long-term therapy is documented.
When NOT to Use the E11 Series
A child with prediabetes or abnormal glucose findings should not be coded with E11.x. Instead:
R73.03 – Prediabetes
R73.9 – Hyperglycemia, unspecified (if diabetes is not diagnosed)
This avoids overcoding and maintains accuracy for early-stage glucose abnormalities in children.
Diagnostic Clarity Is Essential
Children may have:
Obesity
Insulin resistance
Atypical presentations
Overlapping features of T1DM or MODY
If the clinician does not explicitly diagnose Type 2 diabetes, the coder should not assume the type. Follow ICD-10-CM guidelines:
If diabetes type is unspecified, default to Type 2 unless the provider indicates otherwise
Conclusion
Accurate coding for Type 2 diabetes relies on understanding how ICD-10-CM organizes the E11 category and how complications should be linked based on clinical documentation. The ICD-10-CM Official Guidelines for Coding and Reporting clearly state that when the provider does not specify the type of diabetes, the default is Type 2 diabetes mellitus. They also instruct coders to “code the highest level of specificity” and use combination codes when diabetes directly causes a secondary condition.
The Centers for Medicare & Medicaid Services (CMS) further emphasize the importance of complete complication coding for accurate risk adjustment and reimbursement. Conditions such as CKD, neuropathy, retinopathy, and chronic ulcers significantly impact a patient’s clinical profile and must be captured using the appropriate E11.x subcodes along with the corresponding secondary codes (e.g., N18.x for CKD or L97.x for ulcers). CMS’ Hierarchical Condition Category (HCC) guidelines highlight that diabetes with chronic complications carries different risk weights than uncomplicated diabetes, reinforcing the need for proper specificity. Avail our billing support for chronic care and complex conditions.
Clinical standards also align with these coding rules. The American Diabetes Association (ADA) acknowledges that diabetes-related kidney disease, neuropathy, retinopathy, and vascular disease are among the most common long-term complications of Type 2 diabetes, and ICD-10-CM reflects this by dedicating entire subcategories to these conditions. ADA guidance confirms that documentation should clearly state when complications are attributable to diabetes, which directly supports the structure of ICD-10’s combination codes.
By following these official guidelines and using the appropriate E11.x codes, coders ensure:
More accurate claim submission
Fewer denials and audits
Proper reflection of clinical severity
Compliance with CMS and ADA standards
Accurate population-based reporting and risk adjustment
With consistent application of ICD-10-CM rules and a clear understanding of how complications are classified, coders can confidently assign the correct diagnosis codes and support both clinical integrity and compliant billing.
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