Something that we see frequently is multiple diagnosis codes related to the same body area being selected and billed on the claim. Most commonly:   

J02.0: Streptococcal pharyngitis 

J02.9: Acute pharyngitis, unspecified 

J03.90: Acute tonsillitis, unspecified 

R07.0: Pain in throat 

Since these diagnosis codes are related to the same body area, describing the same issue, we are seeing insurance deny whole claims when 2 or more of these diagnosis codes are billed together. Only one of these is necessary for the claim.