Assigning COPD Dx: Not as Simple as It Seems
At first glance, diagnosis coding for chronic obstructive pulmonary disease, more commonly known as COPD, seems like a cinch. ICD-9-CM links “obstructive pulmonary disease [COPD]” to 496 Chronic airway obstruction, not elsewhere classified. Easy!
Except … does that “not elsewhere classified” make you a bit nervous? Aren’t three-digit ICD-9-CM codes usually best avoided due to lack of specificity?
In fact, COPD is a generic term to describe symptoms that may occur as part of another, more specific condition. By the same token, 496 is a catch-all diagnosis, appropriate only when a more precise disease process has not been identified.
Specifically, you shouldn’t report 496 with chronic bronchitis (491.xx), emphysema (492.x), or asthma (493.xx). Just as shortness of breath is “part of” pneumonia, COPD is included within categories 491-493.
In total, there are 24 distinct ICD-9-CM code listings with which you should not list COPD separately. As the ICD-9-CM manual advises, “Due to the overlapping nature of conditions that make up COPD, it is essential that the coder review all instructional notes carefully.”
For example, the physician documentation lists COPD and chronic bronchitis. Proper coding is 491.0 Simple chronic bronchitis because chronic bronchitis is the more specific code, which includes the COPD. If documentation lists COPD and asthma, you would report 493.2x Chronic obstructive asthma. Per Coding Clinic (Second Quarter 1990, page 20), “When a diagnosis of asthma is documented with COPD, 493.2x is assigned whether or not the physician states ‘chronic obstructive’ asthma. Codes 493.0x, 493.1x, and 493.9x are used to classify asthma in patients without chronic obstructive lung disease.”