Which of the following lists drug tiers from least to most expensive cost share?

The correct answer organizes the drug tiers in a way that reflects typical cost-sharing arrangements found in Medicare drug plans.

Starting with preferred generics, this tier generally features the least expensive medications, which insurance plans often encourage patients to use. Next, generics are also low-cost but can be slightly more expensive than preferred generics, as they are not always the primary choice the insurer wants patients to utilize. The preferred brand tier follows, where brand-name drugs that are more widely used and have negotiated lower prices appear. Finally, nonpreferred drugs typically represent the highest cost share to patients, as these are usually brand-name drugs that are not favored by the plan due to higher prices or availability of lower-cost alternatives.

This ranking effectively aligns with how most coverage plans structure their formularies to incentivize the use of lower-cost medications first, while still providing access to other drugs, albeit at a higher cost.