The United States currently uses the ICD-10-CM, a Clinical Modification of the World Health Organization standard for diagnoses adapted for insurance reimbursement and billing purposes.
[5] Several online resources can help locate ICD codes: A good place to start is to contact an advocacy organization for the rare disease.
Many disease advocacy organizations also have medical advisory boards or physician directories, which can help to find someone with experience coding for that particular condition.
[2] Orphanet is a European reference portal for information on rare diseases and orphan drugs.
The Orphanet database also often includes coding information for the Online Mendelian Inheritance in Man, the Unified Medical Language System, and more.