Diabetes Coding

Frances J. Hood, MLS, RHIA


South Med J. 2002;95(1) 

In This Article


Beyond the human suffering, disability, and loss of life that result, diabetes costs the United States about $100 billion a year in direct and indirect costs.[1] The full cost of diabetes is difficult to measure. Death records often fail to reflect the role of diabetes because ICD-9 coding rules call for the assignment of a single cause of death, which may overlook some medical conditions -- such as diabetes -- that may have played a role in the death but that were not sufficiently significant to be considered the actual cause of death. The costs related to undiagnosed diabetes are unknown.

Improving nutrition and increasing physical activity are ways to delay the progression of diabetes. Other ways known to help are controlling blood glucose levels and improving access to proper medical treatment. As of October 2001, 46 states have some types of laws requiring health insurance coverage to include treatment for diabetes.[2]

The National Center for Health Statistics (NCHS) is the Federal Government's principal vital and health statistics agency. Since 1960, the agency has provided a wide variety of data with which to monitor the nation's health. The physician has the opportunity to provide more complete and more accurate data for analysis through quality documentation and correctly coded claim form submission. Correct diagnosis coding of diabetes is critical to appropriate payment for services. It is also provides sound authority to support the future financing of healthcare.

Physicians are responsible for the accuracy and completeness of the information submitted on a bill. The Health Insurance Portability and Accountability Act (HIPAA) requires the use of ICD-9-CM and its Official ICD-9-CM Guidelines for Coding and Reporting by most health plans (including Medicare) by October 16, 2002. The ICD-9-CM Coding Guidelines for Outpatient Services, which is part of the Official ICD-9-CM Guidelines for Coding and Reporting, provides guidance on diagnosis coding specifically for outpatient facilities and physician offices.

ICD-9-CM diagnosis codes are composed of codes with 3, 4, or 5 digits. Codes with three digits are included as the heading of a category of codes that may be further subdivided by the use of fourth and/or fifth digits to provide greater specificity (Table). Assign the codes for both the manifestation and underlying cause; code first the underlying disease. The codes for manifestations cannot be used (designated) as principal diagnosis. Conditions that are integral to the disease process should not be assigned as additional codes.

There has been some confusion about the meaning of "highest degree of specificity" and "reporting the correct number of digits." In the context of ICD-9-CM coding, the highest degree of specificity refers to assigning the most precise ICD-9-CM code that most fully explains the narrative description of the symptom or diagnosis. An example follows: A patient is referred to a physician with a diagnosis of diabetes mellitus. However, there is no indication that the patient has diabetic complications or that the diabetes is out of control. It would be incorrect to assign code 250 since all codes in this series have five digits. Reporting only three digits of a code that has five digits would be incorrect. One must add two more digits to make it complete. Because the type of diabetes (adult onset/juvenile) is not specified, and there is no indication that the patient has a complication or that the diabetes is out of control, the correct ICD-9-CM code would be 250.00. The fourth and fifth digits of the code would vary depending on the specific condition of the patient. One should be guided by the code book.[3]


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.