12.2 Group Underwriting and Contribution/Participation
Key Takeaways
- Contributory plans (employees share premium) require about 75% participation; noncontributory plans (employer pays 100%) require 100% of eligible employees.
- Community rating ignores group claims; experience rating sets premiums from the group's own loss history; manual rating uses standard tables.
- Credibility weights how much of a group's own experience is used; larger groups receive higher credibility.
- Higher required participation lowers adverse selection, so insurers tie minimum participation to whether the plan is contributory.
- Employer-paid group health premiums are generally tax-deductible to the employer and not taxable income to employees.
Once a group is eligible, the insurer must price it and decide how many members must enroll. Two linked ideas drive the national exam here: rating methods (how the premium is built) and participation/contribution rules (how the plan is funded and how many must join). Both exist to keep the pool balanced.
Rating Methods
| Method | Basis | Typical use |
|---|---|---|
| Community rating | Same rate for all groups in an area; ignores a group's own claims | Small-group/individual ACA markets |
| Manual rating | Standard rate tables by class/age/industry | New or small groups with no history |
| Experience rating | The group's own past claims drive the premium | Large groups (often 500+) |
Large groups can be experience rated because their claims are statistically credible. Small groups lack credible data, so insurers fall back on community or manual rates.
Credibility and the Blended Premium
Credibility is the statistical weight given to a group's own claims. A small group's experience is unreliable, so the insurer blends it with the manual rate.
Blended Premium = (Credibility x Group Claims) + ((1 - Credibility) x Manual Rate)
Worked Example
- Group's actual claims last year: $800,000
- Manual-rate premium for a similar group: $1,000,000
- Credibility assigned: 70%
Blended Premium = (0.70 x $800,000) + (0.30 x $1,000,000) = $560,000 + $300,000 = $860,000
The better-than-expected claims pull the premium below the $1,000,000 manual rate, but only to the extent the group's data is credible. A 100%-credible (very large) group would be charged the full $800,000; a 0%-credible (tiny) group would pay the $1,000,000 manual rate.
Contribution and Participation
Whether employees help pay determines how many must enroll. This is the single most tested numeric pair in group health.
| Plan type | Who pays | Minimum participation |
|---|---|---|
| Noncontributory | Employer pays 100% | 100% of eligible employees |
| Contributory | Employer and employee share | ~75% of eligible employees |
Why the Thresholds Differ
In a noncontributory plan employees pay nothing, so there is no reason for a healthy employee to opt out — the insurer can require 100% enrollment, eliminating adverse selection. In a contributory plan employees must pay, so some healthy workers decline; requiring 75% still guarantees a broad enough spread of risks.
Trap: Do not confuse the 75%/100% participation thresholds with cost-sharing percentages. The 75% is how many people must enroll, not how much the employee pays.
Taxation of Group Health
Group medical premiums receive favorable federal tax treatment, a frequent exam point.
| Item | Tax treatment |
|---|---|
| Employer-paid premiums | Deductible business expense for the employer |
| Employer contribution to employee coverage | Not taxable income to the employee |
| Employee share via Section 125 | Paid pre-tax, reducing taxable wages |
| Benefits received (medical) | Generally not taxable to the employee |
Contrast with Disability Income
The medical rule (benefits tax-free) does not automatically apply to group disability income. If the employer paid the premium and did not include it in the employee's income, disability benefits are taxable.
If instead the employee paid premiums with after-tax dollars, the benefits are received tax-free. Examiners love to mix these up, so anchor on: who paid with pre-tax dollars determines whether the benefit is taxed.
How the Pieces Fit Together
The exam treats rating and participation as two halves of one anti-selection strategy. Rating answers "what does this group cost," and participation answers "how many must enroll so the price holds." A small group cannot be trusted to its own claims because a single catastrophic case would distort the rate, so the insurer leans on manual or community rating and demands high participation. A large group generates statistically credible experience, so the insurer can experience-rate it and reward good loss history with a lower premium.
Credibility is the bridge between the two: the larger and more stable the group, the more weight its own claims carry in the blended premium, and the less the manual rate matters.
When you see a blended-premium calculation, plug the numbers into the weighting formula and remember the intuition — favorable claims pull the premium down only to the extent the group's data is believable. A fully credible group is charged its actual experience; a non-credible group is charged the manual rate; everything in between is a weighted average. Examiners often give a credibility percentage and two dollar figures and ask for the blended result, so practice the arithmetic until it is automatic.
The participation thresholds are the single most reliable numeric pair in this chapter: 100 percent enrollment for noncontributory plans (the employer pays the entire premium, so no healthy employee has a reason to decline) and roughly 75 percent for contributory plans (employees pay a share, so some healthy lives opt out, but the threshold still guarantees a broad spread of risk). Do not confuse these enrollment percentages with cost-sharing percentages; the 75 percent figure is how many people must join, not how much the employee pays.
| Concept | Question it answers | Anti-selection role |
|---|---|---|
| Rating method | What premium to charge | Match price to risk |
| Credibility | How much to trust the group's claims | Stabilize small-group rates |
| Participation rule | How many must enroll | Keep the pool broad |
Exam Trap: Group medical benefits are received tax-free, but group disability income benefits are taxable when the employer paid the premium with pre-tax dollars. Always trace who paid with pre-tax money to decide whether the benefit is taxed.
A contributory group health plan requires what minimum participation of eligible employees?
A group's actual claims were $600,000, the manual-rate premium is $1,000,000, and the insurer assigns 60% credibility. What is the blended premium?