12.2 Group Underwriting and Contribution/Participation

How Group Premiums Are Set

Group premiums depend on the rating method, which is driven largely by group size. Larger groups have more statistically credible claims experience, so insurers rely more heavily on the group's own losses.

• Community rating — everyone in a geographic pool pays the same rate; the group's own claims do not move the price.
• Manual rating — standard table rates for similar industries/demographics.
• Experience rating — the group's actual claims history adjusts its premium.

Experience Rating — Worked Example

Experience rating blends the group's own claims with the manual rate, weighted by credibility:

New Premium = (Credibility × Group Claims) + ((1 − Credibility) × Manual Rate)

Given group claims of $800,000, a manual rate of $1,000,000, and 70% credibility:

• Group portion: 0.70 × $800,000 = $560,000
• Manual portion: 0.30 × $1,000,000 = $300,000
• Blended premium = $860,000

Because the group ran better than the manual rate, the blend pulls the premium below the manual rate. A group with worse-than-expected claims would be pulled above it.

Contributory vs. Noncontributory Plans

Who pays the premium determines the minimum participation the insurer requires to keep the pool healthy. This is one of the most heavily tested numeric facts on the exam.

The logic: if employees pay nothing (noncontributory), everyone enrolls automatically, so 100% participation is achievable and adverse selection is minimal. When employees must contribute, some opt out, so the insurer demands at least 75% to avoid a pool skewed toward the sick.

Why Participation Rules Exist

Participation minimums, waiting periods, and active-work requirements all serve one purpose: preventing adverse selection. Without them, healthy employees would skip coverage until they got sick, leaving the insurer with a high-claims pool and forcing rates up.

Other safeguards include:

• Probationary period — discourages job-hopping purely to obtain coverage.
• Active-work requirement — ensures the employee is genuinely working.
• Defined eligible classes — classifications must be based on bona-fide employment criteria (salaried, hourly, executive), never on health status.

Testing Participation in Practice

Participation is tested as a pass/fail screen. Suppose an employer has 40 eligible employees and offers a contributory plan. The insurer requires 75%, so at least 30 must enroll (0.75 × 40 = 30). If only 26 sign up, the insurer can decline or terminate the group because the pool is too thin and exposed to adverse selection.

For a noncontributory plan with those same 40 employees, all 40 must be covered — there is no opt-out, because the employer pays 100% of the cost. A common distractor offers a 50% or 65% threshold; neither is the standard answer for group health.

Taxation of Group Health Premiums

For employer-sponsored medical coverage, the tax treatment is favorable on both sides:

• Employer contributions are a deductible business expense and are not taxable income to the employee.
• Employee contributions can be made pre-tax through a Section 125 cafeteria plan, lowering taxable wages.
• Benefits (medical claim payments) are received tax-free.

Contrast this with employer-paid group disability income, where benefits become taxable to the employee because the premium was paid with untaxed dollars — a classic exam contrast point. The principle: dollars taxed going in come out tax-free, while untaxed dollars going in produce taxable benefits.

Renewal Underwriting and Rate Triggers

Group underwriting does not stop at issue. At renewal the insurer re-rates the group based on updated claims experience, demographic shifts, and enrollment changes. A group whose claims spiked may face a higher renewal rate; a group that grew younger or larger may see a credit.

Insurers also watch for participation slippage — if enrollment in a contributory plan drops below 75% mid-term, the carrier may require corrective enrollment or non-renew. Because these rate moves follow the group's own behavior, the employer has a direct incentive to maintain wellness, accurate eligibility records, and steady participation.

Credibility, Pooling, and Small-Group Rules

Credibility measures how statistically trustworthy a group's own claims are. A 5-life group has near-zero credibility — one heart attack would distort its rate — so insurers pool tiny groups and price them by community or manual rates. As headcount rises, credibility approaches 100% and the group's experience dominates its premium.

Under the ACA's small-group rules, insurers generally cannot vary rates by health status; allowed rating factors are limited to age, geography, tobacco use, and family size. This is why a small employer with one sick worker is still protected from a health-based surcharge, even though large self-funded groups feel claims directly through experience and stop-loss settle-up.

Loss Ratios and the Rate Review Logic

Underwriters and regulators watch the loss ratio — claims paid divided by premiums collected. If a group runs an 85% loss ratio (it consumed 85 cents of claims for every premium dollar), the insurer has little margin and will press for a renewal increase. The ACA's medical loss ratio rule reinforces this from the consumer side, requiring large-group insurers to spend at least 85% of premium on care or issue rebates.

For the exam, connect the dots: experience rating, credibility, participation minimums, and loss-ratio monitoring are all tools aimed at one outcome — pricing the group's true risk while keeping the pool broad enough to stay affordable.