12.2 Group Underwriting and Contribution/Participation

Group Underwriting and Contribution/Participation

Group underwriting differs fundamentally from individual underwriting. The insurer evaluates the risk characteristics of the whole group, not the health of each person. No individual is typically required to submit evidence of insurability when they enroll on time. The underwriter instead studies the group's composition to estimate expected claims and set the rate.

Key factors the insurer weighs include group size (larger groups are more predictable because the law of large numbers applies), age and gender composition (an older or female-heavy group has higher expected claims), industry or occupation (hazardous fields such as mining or roofing raise rates), geography (local medical costs vary widely), prior claims experience (past loss history predicts future cost for larger groups), and plan design (richer benefits and lower cost-sharing raise premium). These factors feed the rating method the insurer chooses.

Why Participation Defeats Adverse Selection

The participation rule exists because employees free to opt out tend to do so only when healthy, leaving a sicker, costlier pool. Requiring 75% enrollment in contributory plans (100% in noncontributory) forces healthy lives into the pool, stabilizing the rate. A late enrollee who declined at first eligibility can be required to show evidence of insurability, precisely because the delayed choice signals possible adverse selection. The exam reliably pairs the participation percentages with the contribution structure, so memorize the 75/100 split.

Manual, Experience, and Blended Rating

Insurers set group rates three ways. Manual (community) rating uses standard tables for small groups with no credible history. Experience rating adjusts the rate using the group's own claims, available once a group is large enough to be statistically credible. Blended rating mixes the two as a group grows. The exam point: the larger and more credible the group, the more its own experience drives the rate, which is why a large employer's renewal can swing sharply after a bad claims year while a small employer's rate tracks the broader community pool.

Worked Scenario: Participation Failure

An employer with 100 eligible employees offers a contributory plan but only 60 enroll — below the 75% minimum. The insurer may decline to issue or may re-rate the group, because the low participation signals adverse selection (the healthy opted out). Switching to a noncontributory design, where the employer pays 100% of the premium, forces 100% participation automatically and removes the adverse-selection problem. The exam pairs the 75%/100% thresholds with the contribution structure and uses participation shortfalls as the trigger for re-rating or declination.

Community Rating vs. Experience Rating

There are two principal group rating methods, and the exam wants you to tell them apart:

Under the ACA's modified (adjusted) community rating for small groups and individuals, premiums may vary only by four factors: age (max 3:1 ratio), geographic area, family size (tier), and tobacco use (max 1.5:1). Health status and gender may not be used. Large self-experienced employers fall outside these limits, so their renewal rate can swing sharply year to year based on their own claims.

Worked Example — Experience Rating Refund

A large employer pays $1,200,000 in annual premium. The insurer's retention (administration, profit, risk charge) is 12%, leaving $1,056,000 available for claims. Actual paid claims are $900,000. The favorable experience produces an experience refund (dividend): $1,056,000 − $900,000 = $156,000 returned to the group.

If claims had instead been $1,100,000, the $44,000 deficit would carry forward and push next year's renewal rate up. This is why experience-rated groups have a strong incentive to promote wellness and control utilization — they directly bear the cost of bad experience and reap the reward of good experience.

Contribution and Participation Requirements

Two trap-laden terms anchor most group exam questions: contribution (who pays the premium) and participation (what share of eligible employees must enroll). They are linked: the more employees pay, the more they can opt out, so the higher the required participation to defeat adverse selection.

Contributory vs. Noncontributory Plans

• Contributory plan — the employee pays part of the premium. Because employees can decline, the insurer requires that at least 75% of eligible employees enroll. The employer must still contribute, and there must be an enrollment requirement to prevent adverse selection.
• Noncontributory plan — the employer pays 100% of the premium. Because no employee pays anything, 100% of eligible employees must be covered. There is no adverse selection because nobody self-selects out, so coverage is automatic and individual evidence of insurability is not needed.

Memorize the pairing: contributory = 75% participation minimum; noncontributory = 100% participation. (Some carriers use a 70% threshold for contributory plans, but the classic exam answer is 75%.)

High participation defeats adverse selection by forcing in the healthy along with the sick. If too few enroll, the pool skews toward those who expect claims, and rates spiral. A late enrollee who declined and later wants in can be required to show evidence of insurability precisely because that late choice signals possible adverse selection.