ICHPPC-2 is an international classification developed for use by primary care physicians. It is an official modification of ICD-9 and consists of only 362 diagnostic titles, which are directly comparable to arbitrarily selected ICD-9 rubrics. In the United States, third party reimbursement requires physicians to provide coded diagnostic information. These authors have arbitrarily assigned those code numbers from ICD-9-CM that are most likely representative of the type of health problems encountered by family physicians and therefore most appropriate for billing purposes where an ICD-9-CM code is required.