> Ok, so it's _broken_. As a system of recording stuff is it also ... incoherent? Slapping on a bandaid or giving someone tylenol are _services_. "Bitten by duc

> Ok, so it's _broken_. As a system of recording stuff is it also ... incoherent? Slapping on a bandaid or giving someone tylenol are _services_. "Bitten by duck" is a _cause_, and different people bitten by ducks could need different services, and people impacted by different causes could need the same services. As others have explained, these are diagnosis codes; there are also procedure codes. Procedure codes are the primary thing billed for, the diagnosis code is just to justify the procedure - some doctors will perform (or falsely claim to have performed) medically irrelevant procedures as a form of billing fraud, and cross-checking the procedure and diagnosis is meant to prevent that. And the reason why there are so many diagnosis codes, is because their primary purpose is public health statistics not insurance billing; and ICD codes are global (although the US also adds its own US-specific ones.) Probably, somewhere in the world, some bureaucrat is tracking the public health cost of animal attacks by species, and those species-specific animal attack codes exist to enable them to do that.