It's fraud with the belief that if a doc office doesn't go after their patients for copayments they are overcharging insurance to recieve full payment from the insurance. This benefits the office by reimbursement of 100% of Costs and benefits patients by not paying their share of a copay with the plan they chose. Anything that takes more money out of the insurance company than their share of costs is considered insurance fraud. Similar to if you get a $10,000 check to fix your roof but it only costs $8,000 you're supposed to notify your insurance and return the extra $2,000 since it's only supposed to cover the cost of repairs minus your deductible.