Chronic obstructive pulmonary disease, most often referred to by its shorthand COPD, is a major respiratory ailment affecting over 11 million Americans every year. In fact, this condition is so widespread that its cause, the underlying chronic lower respiratory disease (CLRD), is the third highest cause of death in the United States, putting it above even car accidents and strokes. As such, it is critical to know how to code this disease, as well as the other conditions that often come along with it.

For starters, patients with COPD often have additional problems due to asthma, but this additional complication is coded differently depending on the type. If the COPD is unspecified and the asthma is both unspecified and uncomplicated, then its diagnosis is lumped in with the single ICD-10 code of J44.9 (Chronic obstructive pulmonary disease, unspecified). If, however, the asthma is specified to be exacerbated, then it needs its own individual code. In this case, code the COPD with J44.9 and code the asthma separately with J45.901 (Unspecified asthma with (acute) exacerbation).

Different rules apply to different forms of emphysema as well. Since emphysema in a more specific type of chronic obstructive pulmonary disease, coding J43.9 (Emphysema, unspecified) is sufficient when these conditions are present. Because both J43 (Emphysema) and J44 (Other chronic obstructive pulmonary disease) have mutual Excludes1 notes, all emphysema that doesn’t include chronic bronchitis will fall somewhere under J43. If the emphysema does include bronchitis, code it with J44.9.

On the other hand, patients who have both COPD and pneumonia will always require separate codes. If the COPD is standard, code both J44.0 (Chronic obstructive pulmonary disease with acute lower respiratory infection) and J18.9 (Pneumonia, unspecified organism). If the patient has exacerbated COPD instead, then code both of these as well as J44.1 (Chronic obstructive pulmonary disease with (acute) exacerbation).