Question: I can’t find any information in the ICD-10 Official Guidelines, and I’m wondering when I should assign a code for an acute condition versus a chronic one? Oklahoma Subscriber Answer: You are correct — the ICD-10 Official Guidelines don’t specifically break down the difference between acute and chronic conditions. ICD-10 Official Guidelines, Section I.B.8, “Acute and Chronic Conditions,” does specify how to sequence conditions that are described as both acute (subacute) and chronic. In situations where the same condition is described as both acute and chronic, and there are different codes in the Alphabetic Index with the same indentation level, you’ll assign both codes with the acute code sequenced first. There doesn’t appear to be a definitive timeframe for what makes a condition “chronic.” For example, the Centers for Disease Control and Prevention (CDC) describes chronic conditions as those that persist for one year or longer (www.cdc.gov/chronicdisease/about/index.htm). The AMA CPT® guidelines for evaluation and management (E/M) coding lists a stable, chronic illness as “A problem with an expected duration of at least one year or until the death of the patient.” Meanwhile, three conditions the American Lung Association lists as chronic include chronic obstructive pulmonary disease (COPD), chronic bronchitis, and chronic cough, the last of which is defined as “a persistent cough that lasts for at least eight weeks, and often much longer” (www.lung.org/lung-health-diseases/lung-disease-lookup/chronic-cough). You may also receive differing information regarding acute conditions. In some cases, the ICD-10 code set offers guidance. For example, I21.- (Acute myocardial infarction) features an Includes note of “myocardial infarction specified as acute or with a stated duration of 4 weeks (28 days) or less from onset.” This vast difference in definitions makes it clear that you can’t determine acute conditions from chronic ones using timeframe alone. At the end of the day, whether a condition is defined as acute or chronic comes down to your provider’s judgment. If your provider’s documentation lists acute or chronic, then that is how you will determine your code assignment. If your provider’s documentation does not specify, then consider querying the provider to clarify which it is from the provider’s perspective.