1. Any insurance plan by which a number of employees of an employer (and their dependents), or members of a similar homogeneous group, are insured under a single policy (master contract), issued to their employer or the group with individual certificates of insurance given to each insured individual or family. Usually, group insurance has lower monthly premiums compared with individual insurance. Group insurance is usually experience rated. Also called group insurance or blanket insurance . 2. Under the Health Insurance Portability and Accountability Act (HIPAA), an employee welfare benefit plan (as defined by ERISA) including any insured or self-insured plan that provides medical care including items and services paid for as medical care to employees or dependents either directly or through insurance, reimbursement, or otherwise if (a) the plan has 50 or more participants or (b) is administered by an entity other than the employer that established and maintains the plan. Also called group health coverage .