A Drug Identification Number, or DIN, is an eight-digit number assigned by Health Canada to every drug product sold in Canada. The DIN uniquely identifies the manufacturer, product name, active ingredients, strength, pharmaceutical form, and route of administration. Insurance companies use DINs to process drug claims — when you fill a prescription, the pharmacist submits the DIN to your insurer to determine eligibility and reimbursement. If a drug does not have a DIN (such as some natural health products, which have an NPN instead), it may not be covered under your drug plan unless the plan specifically includes natural health products. Checking whether a medication's DIN is on your plan's formulary is the most reliable way to confirm coverage before filling a prescription.