Is it possible to have a single plan and two rates?

The scenario is that the company wants to be able to offer a lower premium for medical plan. Essentially, there’s still one medical plan but two different premiums. The standard premium and the lower premium. For the year 2019, everyone should be defaulted to the lower premium during open enrollment. If the employee completes certain wellness requirements by a pre-established date in 2019, then the employee should automatically receive the lower premium for 2020, and if not compliant, then should receive the standard premium for 2020.

To achieve this, is it even possible to have two different rates for the same plan or should we define a new plan for the lower premium