Deductible:
The amount you owe for health care services before your health insurance or plan begins to pay. For example, if your deductible is $1,000, your plan won’t pay anything until you have met your $1,000 deductible for covered health care services subject to the deductible. The deductible may not apply to all services.

Co-pay:
A fixed amount (for example, $25) you pay for a covered health care service, upon receipt of  the service. The amount can vary by the type of covered health care service received.

Patient balance:
The amount of money a patient owes after insurance is billed for services.  This amount reflects the total fee allowance (contracted rate) minus the amount the insurance company paid for the services.  If there is a difference between the billed fee and the allowed (contracted) rate, this amount is written off by the health care provider.