E11.65

Type 2 diabetes mellitus with hyperglycemia

Type 2 diabetes mellitus with hyperglycemia (E11.65) describes a clinical state where a patient with established type 2 diabetes presents with blood glucose levels exceeding the therapeutic target range. This condition is primarily driven by a combination of peripheral insulin resistance—where cells in the muscle, fat, and liver fail to respond normally to insulin—and a progressive decline in pancreatic beta-cell function. Hyperglycemia is typically defined as a fasting plasma glucose level above 126 mg/dL or a random plasma glucose level above 200 mg/dL, although clinical targets are individualized based on age, comorbidities, and risk of hypoglycemia. Acute, severe hyperglycemia can lead to Hyperosmolar Hyperglycemic State (HHS), characterized by extreme dehydration and serum hyperosmolality, which is a medical emergency. Chronic hyperglycemia is the fundamental driver of diabetic complications, causing irreversible damage through pathways such as the formation of advanced glycation end-products (AGEs) and increased oxidative stress, eventually leading to microvascular damage (retinopathy, nephropathy, neuropathy) and macrovascular disease (coronary artery disease, stroke, peripheral artery disease).

Clinical Symptoms

Increased thirst (polydipsia)
Frequent urination (polyuria)
Nocturia (frequent urination at night)
Blurred vision due to osmotic lens changes
Extreme fatigue and lethargy
Unexplained weight loss despite increased appetite
Slow-healing sores or wounds
Recurrent infections such as yeast infections or urinary tract infections
Headaches
Difficulty concentrating or brain fog
Dry, itchy skin
Fruity-smelling breath (less common in type 2 than type 1 but possible)

Common Causes

Peripheral insulin resistance in skeletal muscle and adipose tissue
Progressive pancreatic beta-cell dysfunction and failure
Excessive hepatic glucose production (gluconeogenesis)
Obesity and excess visceral adipose tissue
Physical inactivity and sedentary lifestyle
Genetic predisposition and family history of metabolic disease
Inadequate adherence to insulin or oral hypoglycemic agents
Physiological stress from acute illness, infection, or surgery
Side effects of certain medications such as corticosteroids
High intake of processed carbohydrates and simple sugars

Documentation & Coding Tips

Explicitly link hyperglycemia to the type of diabetes using 'with' or 'due to' in the clinical assessment.

Example: Assessment: Type 2 diabetes mellitus with hyperglycemia. Patient presents with a fasting fingerstick of 286 mg/dL. This is an acute exacerbation of her chronic condition, currently managed with Metformin 1000mg BID. Plan: Increase Lantus dose and monitor for 2 weeks. Coding: E11.65 (Type 2 diabetes mellitus with hyperglycemia) is supported by the direct link between the diagnosis and the clinical finding of elevated glucose.

Billing Focus: Direct linkage documentation to support the 'with' relationship in the ICD-10-CM Alphabetic Index.

Document if the patient is on long-term insulin or injectable non-insulin antidiabetic drugs as these are essential secondary codes.

Example: 65-year-old male with Type 2 diabetes mellitus with hyperglycemia. Current fingerstick 310 mg/dL. Patient has been on long-term insulin glargine for 5 years. Documentation of insulin use allows for the addition of Z79.4, which affects the patient's complexity profile in risk adjustment models.

Billing Focus: Inclusion of Z79.4 (Long term (current) use of insulin) or Z79.84 (Long term (current) use of oral hypoglycemic drugs).

Distinguish between hyperglycemia and diabetic ketoacidosis or hyperosmolar hyperglycemic state.

Example: Type 2 diabetes mellitus with hyperglycemia. Patient is symptomatic with polyuria but negative for ketones in urine and has a normal anion gap, ruling out DKA (E11.10). Blood glucose 350 mg/dL. This specificity ensures the correct 'with' manifestation is selected rather than a more severe metabolic crisis.

Billing Focus: Specificity of manifestation to avoid downcoding or upcoding for DKA/HHS.

Specify the cause of hyperglycemia such as non-compliance, infection, or medication side effects.

Example: Type 2 diabetes mellitus with hyperglycemia. Recent fingersticks ranging 250-320 mg/dL. Hyperglycemia likely secondary to acute bronchitis (J20.9). Medication adherence is good. Treating infection to stabilize glucose levels. This provides a clear clinical picture for medical necessity of the visit.

Billing Focus: Documentation of secondary causes justifies the medical decision-making complexity for E/M leveling.

Record 'hyperglycemia' instead of 'poorly controlled' or 'uncontrolled' to align with 2026 ICD-10-CM indexing.

Example: Assessment: Type 2 diabetes mellitus with hyperglycemia. Patient's A1c is 9.8%, and home logs show consistent hyperglycemia. Using the term hyperglycemia allows for the assignment of E11.65, whereas poorly controlled diabetes defaults to E11.9 unless hyperglycemia is specifically documented.

Billing Focus: Use of specific terminology listed in the ICD-10-CM index (hyperglycemia) to ensure E11.65 is captured.

Relevant CPT Codes

99213 - Office or other outpatient visit for the evaluation and management of an established patient, which requires a low level of medical decision making. When using time for code selection, 20-29 minutes of total time is spent on the date of the encounter.
Used for routine follow-up of stable diabetes where hyperglycemia is mild and requires minimal management changes.
99214 - Office or other outpatient visit for the evaluation and management of an established patient, which requires a moderate level of medical decision making. When using time for code selection, 30-39 minutes of total time is spent on the date of the encounter.
Standard for a patient with Type 2 DM and hyperglycemia where medications must be adjusted or new ones added.
99215 - Office or other outpatient visit for the evaluation and management of an established patient, which requires a high level of medical decision making. When using time for code selection, 40-54 minutes of total time is spent on the date of the encounter.
Used when hyperglycemia is severe, symptomatic, or involves significant comorbidities requiring intensive management.
99203 - Office or other outpatient visit for the evaluation and management of a new patient, which requires a low level of medical decision making. When using time for code selection, 30-44 minutes of total time is spent on the date of the encounter.
Initial evaluation of a new patient with a known diagnosis of diabetes and incidental hyperglycemia.
99204 - Office or other outpatient visit for the evaluation and management of a new patient, which requires a moderate level of medical decision making. When using time for code selection, 45-59 minutes of total time is spent on the date of the encounter.
Comprehensive initial evaluation of a new patient with poorly managed hyperglycemia and multiple medications.
82947 - Glucose; quantitative, blood (except reagent strip)
Essential diagnostic test to confirm the degree of hyperglycemia.
83036 - Hemoglobin; glycosylated (A1c)
Determines if hyperglycemia is acute or indicative of long-term poor control.
95251 - Ambulatory continuous glucose monitoring of interstitial tissue fluid via a subcutaneous sensor for a minimum of 72 hours; analysis, interpretation and report
Used to identify patterns of hyperglycemia throughout the day and night.
99401 - Preventive medicine counseling and/or risk factor reduction intervention(s) provided to an individual (separate procedure); approximately 15 minutes
Used for educating patients on lifestyle changes to combat hyperglycemia.
81003 - Urinalysis, by dipstick or tablet reagent for bilirubin, glucose, hemoglobin, ketones, leukocytes, nitrite, pH, protein, specific gravity, therapeutic drug monitoring, etc.; automated, without microscopy
Screening for ketones in the presence of hyperglycemia to rule out DKA.