12.2 Group Underwriting and Contribution/Participation

Group Underwriting Factors and Rating Methods

Group underwriters evaluate the group, not individuals. Key factors include industry/occupational hazard, group size, average age and gender mix, geographic location, and prior claims (loss) experience. Larger groups produce more statistically predictable results, so their own experience carries more weight.

Rating Methods by Group Size

• Community rating — everyone in a geographic area/pool pays the same rate regardless of the group's own claims.
• Manual rating — rates from standard tables for similar groups.
• Experience rating — premium adjusted by the group's actual claims history; the larger the group, the more credible (reliable) that history.

Credibility: Why Group Size Drives Rating

Credibility is the statistical confidence the insurer places in a group's own claims data. A 5,000-employee group generates enough claims each year that last year's loss ratio is a reliable predictor of next year — so the underwriter assigns high credibility and rates almost entirely on the group's own experience. A 12-employee group, by contrast, could see one cancer case swing its loss ratio wildly, so its own data is barely predictive.

That is why small groups are community or manual rated: the insurer pools them with similar groups to smooth out random spikes. As a group grows, the rating gradually blends more of its own experience in. The progression — community/manual → blended → full experience — tracks rising credibility, not the employer's preference.

Exam tip: When a question describes a small group worried that one bad claim year will spike its rate, the protective answer is community/manual rating; the group is too small for credible experience rating.

Worked Numeric: Experience Rating

Experience rating blends the group's own claims with the manual (standard) rate using a credibility factor:

New Premium = (Credibility × Group's Own Experience)
            + ((1 − Credibility) × Manual Rate Premium)

Example: A group's claims last year were $800,000. The manual-rate premium for a similar group is $1,000,000. The group's credibility is 70%.

= (0.70 × $800,000) + (0.30 × $1,000,000)
= $560,000 + $300,000
= $860,000

Because the group performed better than the manual standard, blending in 70% of its favorable experience lowers the premium toward $860,000. A larger group would receive higher credibility, pushing the result even closer to its own $800,000 experience.

Contributory vs. Noncontributory — and Participation Rules

Whether employees share the cost drives the minimum participation requirement, which is the single most-tested number in this section.

Exam tip — memorize: Contributory = 75% minimum participation; Noncontributory = 100%. The logic: when the employer pays everything, everyone is automatically in, so there is no opportunity for healthy employees to opt out (no adverse selection). When employees pay part, the 75% floor forces a broad enough pool.

Why Participation Minimums Exist

If only sick employees enrolled, claims would exceed premiums and the plan would fail. Requiring 75% participation in contributory plans guarantees enough healthy lives to spread risk. Evidence of insurability (EOI) is generally not required at initial enrollment, but a late enrollee — someone who skipped the initial window without a qualifying event — may have to provide EOI or wait until open enrollment.

Counting Participation and the Effect of Other Coverage

Participation is measured against eligible employees, not the total headcount. Employees who waive the plan because they have other creditable coverage — a spouse's plan, Medicare, or military coverage — are typically excluded from the denominator. This matters because a contributory plan can still meet the 75% test even when several workers decline, as long as those declining have valid other coverage.

Worked example: A firm has 100 eligible employees. Ten waive because they are covered under a spouse's plan; the remaining 90 are the relevant pool. If 70 enroll, participation is 70 / 90 = 78%, which clears the 75% contributory minimum. Had the insurer counted all 100, the result would have been 70%, falsely suggesting the group failed.

Trap: Watch for questions that try to count validly-waived employees in the denominator to make a compliant group look noncompliant. Properly waived lives drop out of the participation calculation.

Community Rating vs. Experience Rating

The rating-method choice is driven by group size and regulation. Experience rating sets a group's premium from its own past claims and suits large groups with credible data. Community rating charges all groups in an area the same base rate regardless of claims history and underlies ACA small-group and individual pricing, which permits adjustment only for area, age, tobacco, and family size.

Participation Requirements by Funding Type

The participation threshold flexes with who pays. A noncontributory plan (employer pays 100%) generally requires 100% participation, because there is no reason for an employee to decline. A contributory plan (employees share cost) typically requires about 75% participation. Employees with other coverage (a spouse's plan) are usually excluded from the participation count, so a high opt-out rate driven by spousal coverage does not automatically fail the test — a subtle point examiners use to trap rote memorizers.