Which of the following best describes the cost-sharing structure in original Medicare?

The cost-sharing structure in original Medicare encompasses several components, which is why the correct choice is that it includes premiums, deductibles, and coinsurance.

In original Medicare, beneficiaries are required to pay a monthly premium for Part B (medical insurance), as well as a deductible before Medicare starts to pay its share for services. After reaching the deductible, beneficiaries typically pay coinsurance, which is a percentage of the cost of services, such as an inpatient hospital stay or other medical services. This multi-faceted approach to cost-sharing means beneficiaries often encounter various out-of-pocket expenses depending on the services they receive.

The other options do not capture the comprehensive nature of the cost structure in original Medicare. There is more to cost-sharing than just monthly premiums or copayments, and suggesting that there are no out-of-pocket expenses disregards the reality of deductibles and coinsurance. Thus, recognizing the integral components of premiums, deductibles, and coinsurance is essential for understanding how costs work within original Medicare.