The general rule is that if an employer offers group health coverage to any full-time employees, the employer must offer coverage to all full-time employees.
The employer has the option to offer coverage to part-time employees (defined as those working fewer than 30 hours per week). If the employer offers coverage to any part-time employees, all of them must be offered coverage.
These rules apply regardless of the medical condition of the employees. In other words, any eligible employee can’t be denied coverage based on previous medical problems, known as preexisting conditions.
In addition, any dependents of eligible employees are generally eligible for coverage under a group plan. Dependents include spouses, children, and in some cases, unmarried domestic partners. Dependents cannot enroll for coverage unless the employee has enrolled.
Under the Affordable Care Act, group insurance plans are required to extend coverage to adult dependents through age 26. This only applies in cases where the adult dependent’s employer does not offer coverage. The provision applies to all people under 26, whether or not their employer offers coverage.