An employee cannot choose an effective or start date for employer (group) plans.
Typically group benefits are provided consistently to all employee. Effective dates are calculated using an employee's hire date and the group's waiting period. Once enrolled no changes can be made until the group's Open Enrollment period.
The exception to the open enrollment is Qualifying Life Event. Even then the effective date will be based on the event as noted by supporting documentation.
Schedule a free consultation with a licensed agent to find out about all group premium costs.