12.1 Group Health Fundamentals and Eligibility

Group health insurance provides coverage to a defined group of people, most commonly the employees of a single employer. Unlike individual insurance, the contract is not issued to each insured. Instead, one master policy (master contract) is issued to the group sponsor, and each covered person receives a certificate of insurance that summarizes the benefits. Understanding who holds the contract, who is eligible, and how participation rules guard against adverse selection is foundational on the national exam.

Master Policy and Certificates

The master policy is the actual legal contract. It is negotiated between the insurer and the group sponsor (the policyholder), contains all benefits, exclusions, and conditions, and is the document amended when the plan changes. The certificate is evidence of coverage handed to each member but is not the binding contract.

Exam trap: A question may state an employee relies on the certificate's wording over the master policy. The master policy controls; the certificate is only a summary.

What Qualifies as a Group

A basic licensing rule: a group must have been formed for a reason other than obtaining insurance. A club organized solely to buy a group policy is not an eligible group, because such a group would attract only unhealthy applicants (adverse selection). Eligible group types include single-employer groups, trade and professional associations, multiple-employer welfare arrangements (MEWAs), labor unions, and creditor-debtor groups.

Eligibility Requirements

Group plans define exactly who may enroll. The most common gatekeeping rules are:

• Eligible class - typically full-time employees; under the ACA, full-time means 30 or more hours per week.
• Probationary (waiting) period - a new hire waits a set time (commonly 0-90 days) before coverage starts. The ACA caps the waiting period at 90 days.
• Eligibility period (enrollment window) - after satisfying the probationary period, the employee usually has 31 days to enroll without evidence of insurability.
• Actively-at-work provision - the employee must be performing the normal duties of the job on the date coverage would take effect; an employee home sick that day has coverage deferred until return.

Participation Requirements

Participation rules force a broad cross-section of healthy and less-healthy members into the pool. The rule depends on who pays:

• Contributory plan - employees pay part of the premium; minimum participation is generally 75% of eligible employees.
• Noncontributory plan - the employer pays the entire premium; participation must be 100% of eligible employees.

Worked example: An employer has 200 eligible employees and offers a contributory plan. The insurer requires 75% participation. At least 200 x 0.75 = 150 employees must enroll for the plan to be issued. If only 140 enroll, the insurer can decline or re-rate the group.

Effective Date and the Actively-at-Work Rule

The effective date is when coverage actually begins. For new groups, the master policy states a fixed effective date; for new hires joining an existing plan, coverage usually begins on the first of the month following completion of the probationary period. The actively-at-work provision then acts as a final gate: if the employee is not performing normal duties on that date (for example, hospitalized or on leave), the start of coverage is deferred until they return to active work. This rule prevents an employer from enrolling an employee who is already disabled, which would defeat the pooling principle.

Dependent Eligibility

Group health plans typically extend coverage to the employee's dependents. Under the ACA, an adult child may remain on a parent's plan until age 26, regardless of marital, student, or residency status. A spouse is eligible unless legally separated or divorced. Newborns and newly adopted children are covered automatically for a short window (commonly 31 days), after which the employee must formally add the child and pay any additional premium to continue coverage.

Open Enrollment and Late Entrants

Employees who decline coverage when first eligible become late entrants. To re-enroll, a late entrant generally must wait for the plan's annual open enrollment period or qualify for a special enrollment event (such as marriage, birth, or loss of other coverage). Insurers may impose evidence of insurability or a longer waiting period on late entrants in some markets, again to discourage employees from waiting until they are sick to enroll.

Exam trap: Do not confuse the probationary (waiting) period - the time a new hire waits before becoming eligible - with the eligibility (enrollment) period, the short window during which an eligible employee may enroll without evidence of insurability. They are sequential, not the same thing.

Experience Rating and the Probationary Period

Group health is usually experience-rated (premiums reflect the specific group's past claims) for larger groups and community-rated for small groups. New employees commonly serve a probationary period (a waiting period before coverage starts, often 30–90 days, ACA-capped at 90 days), after which they have an enrollment period to elect coverage. An employee who declines during the enrollment window becomes a late entrant and may face evidence of insurability or a limited annual open enrollment to join later.

Noncontributory vs. Contributory Participation Thresholds

To control adverse selection, a noncontributory plan (employer pays 100%) requires 100% of eligible employees to participate, while a contributory plan (employees share cost) typically requires at least 75% participation. The exam tests these two thresholds and the reason for them: high participation dilutes the proportion of high-risk individuals in the pool.