Hello! Deductible, premium, and copay refer to different things in insurance policies.
The deductible is the amount you have to pay for services before the insurance provider will begin to cover any expenses. The premium is the amount the insurance company charges you monthly or annually for your insurance plan. A copay is a fixed fee you have to pay for a particular type of service that you have to pay regardless of whether you have met your deductible. The copay amount may or may not count towards meeting your deductible, depending on the plan.
For example, suppose you have a health insurance plan with a $500 monthly premium and a $2,000 deductible. The plan also imposes a copay of $20 for a doctor visit and $15 for a drug prescription. In this case, you have to pay your health insurance provider $500 each month (the premium) regardless of what kind of healthcare services you receive - you can think of this as the subscription fee for the plan. The $2,000 deductible means that you have to pay the first $2,000 of your healthcare expenses yourself. Once you exceed that amount, your insurance provider will begin to cover your expenses. The $20 copay for a doctor visit means that you have to pay a flat fee of $20 each time you visit the doctor, regardless of whether you have met your deductible or not.