Discrimination in benefits and waiting periods

[Guest jfgc]

Is it discriminatory to have different waiting periods and benefits for hourly employees and salaried employees. Salaried employees have a 30 day waiting period and hourly employees have a 90 day waiting period. Premiums are pre-taxed. The medical plan is the same for both however, salaried employees have dental and vision coverage under a self-funded plan that the company pays for. Hourly employees have the option of electing dental coverage under a fully insured plan that the employee pays for. When are you required to perform discrimination testing (and how) under a fringe benefit plan/welfare plan? Not sure of the difference. Obviously I need help!