November is American Diabetes Month and there’s no better time to review one of the most common coding variances we see on coding audits: coding for diabetic complications.  Later this month, I will present a webinar on this topic, but for now, let’s get a jump on it by covering the things that stand out to all of us at Haugen during coding audits.

We’ve been operating under the 2021 coding guidelines for a month now and if you haven’t taken time for your annual review of the guidelines, I recommend you start today by reviewing section I.C.4.a., which includes guidelines for coding diabetes mellitus (DM).  DM is an endocrine disorder that allows glucose (sugar) to build up in the bloodstream and tissues.  The excess sugar has a devastating effect on the body’s systems, particularly the nerves, blood vessels, kidneys, and eyes.  The ICD-10-CM classification system includes combination codes for the complications that arise in diabetic patients.

If you are a long time coder who hales back to the days of ICD-9-CM when all diabetes codes were classified to category 250, you may be struggling with the way we code for diabetes in ICD-10-CM.  That is largely because of the “with” convention and the fact that most diabetic complications are indented under “with” following the diabetes main term in the index.  The result of this guideline and indexing is combination codes for most diabetic complications without needing documentation from the physician linking them together. 

I.A.15 “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 (either under a main term or subterm), 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”).

For conditions not specifically linked by these relational terms in the classification or when a guideline requires that a linkage between two conditions be explicitly documented, provider documentation must link the conditions in order to code them as related.

The word “with” in the Alphabetic Index is sequenced immediately following the main term or subterm, not in alphabetical order.

For example, a patient with diabetes, chronic kidney disease (CKD), peripheral angiopathy, and polyneuropathy, combination codes are used to report the connection between diabetes and the three complications based on the indexing:

While I can’t put my finger on how these combination codes are being missed by coders, I have my suspicions.  My first suspicion is that the code was generated by computer assisted coding (CAC) software as a potential code and the coder didn’t “read” the code list before completing the record, thereby incorrectly reporting the condition.  Another possibility is the pressure of productivity standards placed on coders in which they “code as they go” and again fail to review the complete list of codes before completing the account because of time constraints.  There may be some old school coders out there who remember when there had to be a documented link between diabetes and the complication before assigning the combination code – a throwback to our pre-ICD-10-CM days.  Whatever the cause, as auditors, we can easily identify a probable coding error just by looking at the code list before looking at the medical record documentation.

The simple solution to this coding error is thorough review of the codes before completing an account. Annual review of coding guidelines is also important to remind us of the “simple” things we tend to overlook.  If you want to review all of this and learn a few more tricks, be sure to tune in November 19 for my webinar, Coding Diabetes, which will also be available on demand following the live presentation.