12.1 Group Health Fundamentals and Eligibility

Group health insurance covers a natural group of people, most often the employees of a single employer, under one contract. The exam tests how this structure differs from individual coverage and how eligibility rules keep the risk pool healthy. Mastering the master-policy/certificate split and the active-work rule clears a large share of national group questions.

Master Policy and Certificates

The insurer issues one master policy (also called the master contract) to the employer, who is the policyholder. Individual employees do not receive a policy; they receive a certificate of coverage that summarizes their benefits.

Trap: An exam choice may say the certificate is the contract. It is not. Amendments are made to the master policy, and benefit disputes are resolved against the master policy's language.

Group vs. Individual Underwriting

Group coverage is underwritten on the group as a whole, not on each applicant's health. The insurer reviews the group's characteristics rather than ordering medical exams.

Group Underwriting Considerations

• Industry/occupation — hazard level of the work performed.
• Group size — larger groups produce more statistically predictable claims.
• Age and sex distribution — younger pools generally cost less.
• Geographic location — regional medical-cost variation.
• Prior claims experience — the group's loss history.

Because there is no individual underwriting, the insurer relies on structural safeguards to avoid attracting only sick lives. Those safeguards are the eligibility rules below.

Eligibility and the Active-Work Rule

To be a covered participant, an employee normally must clear several gates designed to prevent people from buying in only when they need care.

Active-Work Requirement

The active-work (actively-at-work) requirement states that an employee must be performing the normal duties of the job on the date coverage would take effect. An employee absent due to illness or injury on that date has coverage deferred until they return to active work. This is a classic anti-selection device — it prevents an employee from delaying enrollment until a known medical event, then claiming on day one.

Worked example: A plan's effective date is the first of the month after 60 days. An employee hired June 5 clears probation August 4 and would be effective September 1. If she is hospitalized on September 1, coverage is deferred until she returns to active work.

Dependent Eligibility

Most group medical plans permit the employee to cover dependents. Federal law (ACA) requires plans that offer dependent child coverage to extend it to adult children up to age 26, regardless of the child's marital status, student status, residency, financial dependency, or access to other coverage.

Enrollment Windows

• Initial enrollment — when first eligible.
• Open enrollment — annual window to add/drop coverage.
• Special enrollment — triggered by a qualifying life event (marriage, birth/adoption, loss of other coverage), generally within 30–60 days.

Outside these windows, a late enrollee may face restrictions in non-ACA contexts, which is why timely enrollment matters on exam fact patterns.

Why Group Coverage Behaves Differently

Tie all of this back to one principle the exam returns to repeatedly: group insurance works because the group forms for a reason other than to obtain insurance. An employer's workforce is a natural group, so the insurer is not facing a pool that assembled only because its members expect to file claims. That single fact is why the insurer can skip individual medical exams, issue coverage on a guaranteed basis, and price the whole group rather than each life. Remove the natural-group element and adverse selection returns, which is precisely what the eligibility, participation, and active-work rules are designed to prevent.

Expect questions that contrast the certificate with the master policy in a dispute. When an employee believes a benefit was promised but the master contract excludes it, the master policy governs; the certificate is only a summary and cannot expand or contradict the contract. ERISA adds the Summary Plan Description, a plain-language document the plan must furnish to participants, and creates a federal claims-and-appeals framework. You should be able to say that the employer is the policyholder, the insurer is the carrier, and the employee is the certificate holder, not a party to the contract.

Exam Trap: The active-work requirement is an insurability proxy, not a punishment. An employee out sick on the effective date is not denied coverage; coverage is simply deferred until the employee returns to active duty, at which point it takes effect without new underwriting.

Dependent eligibility rounds out the topic. The ACA sets a federal floor requiring plans that cover dependent children to extend coverage to age 26 regardless of the child's marital status, student status, residence, or access to other coverage, and a child who was disabled and dependent before that age may continue beyond it. Spouse coverage is elective, and many plans extend to domestic partners.

The enrollment windows — initial, annual open enrollment, and special enrollment triggered by a qualifying life event such as marriage, birth, adoption, or loss of other coverage — are common recall items, and missing a window outside the ACA context can leave a late enrollee with restricted coverage.