Co-insurance/Deductible

Co-insurance: Say you have a deductible of 2000 and the hospital bill comes around at 20, 000. As a rule you have to pay off the deductible, i.e. 2000 out-of-pocket before the health insurance company begins to pay. So you still need 18000 to pay off the rest of the bill. If you have a 80/20 co insurance and the insurance company pays 80%, you need to make 20% of the remaining 18,000. This means that your out-of-pocket costs would be deductible + the percentage of co-insurance you have agreed upon.

My question from here is is if you have the deductible of $2000 and your hospital bill is $20,000 and you have not paid off your deductible yet, and you do not have 80/20 coinsurance or a secondary insurance who pays the $18,000? Also if the patient has not paid off the deductible for a service at the time of service, by the time of service or after the date of service, can the patient still receive services? Does the patient have to meet the deductible before getting services or getting durable medical equipment? If the patient has not paid off the deductible yet and received services, will the patient have to pay the coinsurance or billed amount (what will they have to pay)?

If this seems confusing, can you please explain in as much detail as you can how the coinsurance, deductible and getting the service makes sense together (under Medicare with a secondary and another primary with a secondary)? I copied the example above from this site.

Thanks,
Nicholas