Diabetes Mellitus Coding Guidlines

Diabetes Mellitus Coding Guidlines

  • 01 Nov 4
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Diabetes Mellitus Coding Guidelines
Sommer Huseman, RN, Risk Adjustment and Coding Specialist

Diabetes mellitus is a condition that results when the body is unable to produce enough insulin or properly use the insulin that it does produce. The disease of diabetes is present in a significant number of patients and consumes more than $100 million in health care resources in the United States. Therefore, it is important that the guidelines for coding diabetes mellitus are understood. Correct coding of diabetes is critical in determining the correct reimbursement for encounters related to this disease and for tracking health care services provided for this population of patients. An incorrect code may result in a medical necessity denial for outpatient service.

Before assigning a code there are three considerations you must keep in mind.

  1. What type of diabetes does the patient have?
  2. Does the documentation indicate that the diabetes is controlled or uncontrolled?
  3. Are there manifestations or complications and what are they?

The ICD-9-CM code for diabetes is assigned to category 250 Diabetes Mellitus. The fourth digit is determined by the presence of manifestations or complications identified due to diabetes. The fifth digit determines the type of diabetes and whether it is uncontrolled or not stated as uncontrolled.

Types of Diabetes
There are two types of diabetes mellitus: Type I and Type II.  We have seen significant confusion on how to choose the correct type of diabetes to code. Terms like IDDM, NIDDM, adult onset and juvenile are often documented in the medical record but the guidelines for coding using these terms are contradictory and have been open for interpretation. Therefore, effective Oct. 1, 2004, the code descriptions for the fifth-digit selection of category 250 Diabetes Mellitus have been revised as follows. Notice that the revisions remove the terms IDDM type, adult onset type, and non-insulin dependent type from the code descriptions.

0: Type II or unspecified type, not stated as uncontrolled. Fifth-digit 0 is for use for Type II patients, even if the patient requires insulin
1: Type I [juvenile type], not stated as uncontrolled
2: Type II or unspecified type, uncontrolled. Fifth-digit 2 is for use for Type II patients, even if the patient requires insulin
3: Type I [juvenile type], uncontrolled

When determining the type of diabetes, it is important to not take into consideration the patient’s age when diabetes was diagnosed or the fact that the patient receives insulin. As mentioned above, the determining factor in the assignment of the fifth digit for diabetes mellitus is whether the patient is Type I or Type II. If documentation is unclear, then the physician must determine the type through a query. If the type is still unknown, the fifth-digit of 0 or 2 is assigned.

Fifth Digit- Controlled vs. Uncontrolled
Once the type of diabetes is identified, it must be determined if the diabetes is controlled or uncontrolled to assign the appropriate fifth-digit. Uncontrolled diabetes is a nonspecific term indicating that the patient’s blood sugar level is not within acceptable levels based on the patient’s current treatment regimen. Depending on the type of diabetes, code 250.x2 or 250.x3 is used to code uncontrolled diabetes. Uncontrolled diabetes should not be coded unless the physician’s documentation indicates that the diabetes is uncontrolled or out of control.   250.x0 or 250.x1 are used if the documentation indicates the diabetes is controlled OR if no indication about control is noted.

Fourth Digit- Manifestations and Complications
To assign the fourth digit, one must determine if there are any complications or manifestations of the diabetes. If none are present then code 250.0x Diabetes Mellitus without Mention of Complication, is assigned. If present, complications will generally fall into two categories:

  • Acute metabolic complications (250.1x-250.3x)
  • Chronic complications (250.4x-250.8x)

Acute Diabetic Complications
Acute metabolic complications such as ketoacidosis, hyperosmolality with or without coma or other coma will be assigned to one of the following codes:

  • 250.1X, Diabetes with Ketoacidosis
  • 250.2X, Diabetes with Hyperosmolality
  • 250.3X, Diabetes with Other Coma

Because the acute metabolic complication is part of the diabetes itself, an additional code is not required.

Code 250.9X, Diabetes with Unspecified Complications includes those metabolic complications of diabetes that cannot be assigned elsewhere.

Chronic Diabetic Complications
Diabetic patients are susceptible to chronic conditions and complications that affect a number of body systems but primarily the renal, vascular and nervous systems. Chronic or long-standing conditions or manifestations are coded first to the appropriate diabetic code, 250.4X-250.8X, with an additional code to identify the specific complicating condition or manifestation. Diabetic patients will often have more than one complication present at the same time. In these instances more than one code from subcategories 250.4x-250.8x should be used along with a manifestation code (“buddy code”) for each.

Remember that conditions listed with a diagnosis of diabetes or in a diabetic patient are not necessarily complications of the diabetes. There must be documentation that indicates a cause-and-effect relationship between the diabetes and the condition before it can be coded as a diabetic condition. Documentation that indicates a cause and effect relationship includes “due to,” “caused by,” “with” and “secondary to.”  When there is no documentation indicating that the condition is related to the diabetes, code the condition first and the diabetes as an additional code.

Gangrene and osteomyelitis are exceptions to the above rule. There is an assumed relationship between these conditions and diabetes unless there is documentation that specifically indicates that the osteomyelitis/gangrene is due to something other than diabetes.

Chronic renal failure, nephrosis and nephritis are common diabetic complications. To code diabetic nephropathy assign 250.4X and 583.81, Nephritis and nephropathy, not specified as acute or chronic, in diseases classified elsewhere. Diabetic nephrosis and diabetic nephrotic syndrome are coded to 250.4X and 581.81, Nephrotic syndrome in diseases classified elsewhere.  If the chart records Chronic Kidney Disease due to diabetes, then the CKD should be staged and coded as such or else as unspecified 585.9, along with the Diabetes code 250.4x.

 250.5X, Diabetes with Opthalmic Manifestations
Diabetic retinopathy is often seen in diabetic patients. Patients who have been diabetic for a long time and/or those who have poor control of blood sugar levels are more likely to develop diabetic retinopathy. Diabetic retinopathy is coded with 250.5X and 362.0X depending on the type of retinopathy.  Other related diabetic eye conditions may be manifestations also, but should be clearly documented as caused by diabetes.  For example, a senile cataract is not assumed to be a diabetic cataract and therefore is not a ophthalmic manifestation of diabetes.  (Diabetic cataracts do occur uncommonly and would typically be confirmed as such by an eye doctor.)

 250.6X, Diabetes with Neurological manifestations
Peripheral, cranial and autonomic neuropathies are very common chronic manifestations of diabetes. For example, the codes for peripheral (or cranial) neuropathy are 250.6X and 357.2, Polyneuropathy in diabetes. For autonomic neuropathy assign 250.6X and 337.1, Peripheral autonomic neuropathy in disorders classified elsewhere.

 250.7X, Diabetes with peripheral circulatory disorders
Peripheral vascular disease is also a common diabetic complication. Peripheral vascular disease is coded to 250.7X and 443.81, Peripheral angiopathy in diseases classified elsewhere. Diabetic arteriosclerosis with gangrene is coded to 250.7X, 440.2, Arteriosclerosis of arteries of the extremities and 785.4, Gangrene.

Note that diabetes with ischemic heart disease (410-414) and cerebrovascular disease (430-438) are coded as separate entities and are not included in code 250.7X.

Diabetes with Other Manifestations
Diabetic patients often develop foot ulcers that may be due to diabetic neuropathy or peripheral vascular disease. In these instances assign codes 250.6x or 250.7x as appropriate and 707.1x ulcer of lower limbs, except decubitus. If the cause of the diabetic ulcer is not known assign code 250.8x, Diabetes with other specified manifestation. Do realize that all ulcers in diabetic patients are not necessarily diabetic ulcers. If documentation in the medical record is not clear or there is a question as to the relationship between the ulcer and the diabetes, query the physician.



Some helpful summary guidelines on diagnosis for this specific chronic condition:

  • ALWAYS report to the fifth digit
  • Require reporting of an additional diagnosis code for the associated condition (etiology/ manifestation)
  • When assigning codes for diabetes and its associated conditions, sequence the diabetes category code (250.xx) first.
  • Report as many codes from the 250 category as necessary to identify ALL of the associated conditions present.


Not   Stated as Controlled:


Type I

Type II

Type I

Type II

Uncomplicated Diabetes





w/ Ketoacidosis





w/ Hyperosmolarity





w/ Other coma





w/ Renal manifestations





w/ Ophthalmic manifestations





w/ Neurologic manifestations





w/ Peripheral circulatory   disorders





w/ Other specified manifestations   NEC





w/ Unspecified complications






*The information presented here complies with accepted coding practices and guidelines as defined in the ICD-9-CM coding book. It is the responsibility of the healthcare provider to produce accurate and complete documentation and clinical rationale, which describes the encounter with the patient and the medical services rendered, to properly support the use of the most appropriate ICD-9-CM code(s) according to the official coding  guidelines.

*The information presented herein is for general informational purposes for clinicians only and is not warranted that the information contained herein is complete, accurate or free from defects.