The insurance plan you are asking about is typically the plan you choose when you select health insurance coverage. Depending on where you live, it will likely be a private health insurance plan or a public option like Medicare or Medicaid.
The specific plan you choose, whether it's private or public, is the plan you will be responsible for submitting payment to, depending on the coverages within your plan. Generally, you will be responsible for the cost-sharing payments, called copays and/or coinsurance, for each service. In most cases, if you receive services that aren’t covered by your plan you will still be responsible for payment.
For further information, you should review your policy documents, which detail your plan’s coverage requirements. You should also contact your health plan's customer service department to get more specific information about billing and payments. Be sure to ask about any deductibles and copay guidelines your plan may have.
If you have any questions about your insurance plan and the services covered, you should contact your health insurance provider directly. You can find more information about health insurance plans and how they work here: https://www.healthcare.gov/using-insurance/