Coding Diabetes: Time to Look at the Coding Guidelines Again

November is National Diabetes Awareness Month, prompting coders to review the coding guidelines for this disease suffered by more than 10.9 million U.S. residents.

During November, the Centers for Medicare & Medicaid Services (CMS) is raising awareness about diabetes, diabetic eye disease, the importance of early disease detection, and related preventive health services covered by Medicare. According to the CMS website, diabetes can lead to severe complications such as heart disease, stroke, vision loss, kidney disease, nerve damage, and amputation, among others, and it’s a significant risk factor for developing glaucoma. People with diabetes are more susceptible to many other illnesses such as pneumonia and influenza and are more likely to die from these than people who do not have diabetes. Among U.S. residents 65 years and older, 10.9 million (26.9 percent) had diabetes in 2010. Currently, 3.6 million Americans 40 and older suffer from diabetic eye disease. Education and early detection are major components to combating this disease.

Let’s take a look at the coding guidelines for diabetes to ensure that we accurately select and capture the ICD-10-CM code(s) for this disease. As all health information management (HIM) coding professionals know (or should know), the ICD-10-CM Official Coding and Reporting Guidelines have been approved by the four organizations that make up the Cooperating Parties for ICD-10: the American Hospital Association (AHA), the American Health Information Management Association (AHIMA), the Centers for Medicare & Medicaid Services (CMS), and National Center for Health Statistics (NCHS).

These official coding guidelines are organized into four sections. Section I includes the structure and conventions of the classification and general guidelines that apply to the entire classification, as well as chapter-specific guidelines that correspond to the chapters as they are arranged in the classification. Section II includes guidelines for selection of principal diagnoses for non-outpatient settings. Section III includes guidelines for reporting additional diagnoses in non-outpatient settings. Section IV is for outpatient coding and reporting. It is necessary to review all sections of the guidelines to fully understand all of the rules and instructions needed to code properly. Again, Section I applies to all ICD-10-CM coding and all settings, unless otherwise stated.

Within Section I are the chapter-specific guidelines, where you will find the chapter for diabetes: Chapter 4: Endocrine, Nutritional, and Metabolic Diseases (E00-E89). Diabetes mellitus codes falls within the code range E08-E13. These chapter-specific diabetes guidelines contain six primary criteria:

1. Type of diabetes
2. Type of diabetes mellitus not documented
3. Diabetes mellitus and the use of insulin and oral hypoglycemic
4. Diabetes mellitus in pregnancy and gestational diabetes
5. Complications due to insulin pump malfunction 
   (a) Underdose of insulin due to insulin pump failure
   (b) Overdoes of insulin due to insulin pump failure
6. Secondary diabetes mellitus
   (a) Secondary diabetes mellitus and the use of insulin or oral hypoglycemic drugs
   (b) Assigning and sequencing secondary diabetes codes and causes
        (i) Secondary diabetes mellitus due to pancreatectomy
        (ii) Secondary diabetes due to drugs

New revisions for 2018 are the following two sections (3 and 6) for the coding of diabetes (the bolded wording represents the additions/revisions for FY2018):

Of the 19 conventions found in Section I of the guidelines, the “with” instruction (Convention No. 15) often is difficult to grasp, as it relates to diabetes. Here’s what that convention says (note the bolded wording, which represents a change from the prior year):

“With”
The word “with” or “in” should be interpreted to mean “associated with” or “due to” when it appears in a code title, the Alphabetic Index, or an instructional note in the Tabular List. The classification presumes a causal relationship between the two conditions linked by these terms in the Alphabetic Index or Tabular List. These conditions should be coded as related even in the absence of provider documentation explicitly linking them, unless the documentation clearly states the conditions are unrelated or when another guideline exists that specifically requires a documented linkage between two conditions (e.g., sepsis guideline for “acute organ dysfunction that is not clearly associated with the sepsis”).

When looking in the Alphabetic Index, under “diabetes” you will see the “with” immediately listed. There are many terms/conditions that are listed as “with diabetes.” Based on the convention cited above, the coding professional should interpret the “with” to mean “associated with or due to.” There is a presumed causal relationship between diabetes and those listed under “with.” This causal relationship exists even in the absence of provider documentation explicitly linking them.

For example:

Review the listing under “with” carefully and then go to the tabular and confirm the correct code selection (assignment). Also, check for any other guideline that may exist that specifically requires a documented linkage between two conditions, as this will impact code selection.

With the prevalence of diabetes, we need to ensure that we understand and follow the official coding and reporting guidelines so that we have quality coded data.

Now is a good time to review these guidelines again as our nation’s attention is drawn to the condition of diabetes.