Stop-Loss Insurance
Also known as: Stop Loss, Excess Loss Insurance, Specific and Aggregate Stop-Loss
When an employer chooses to self-insure (self-fund) its employee health plan, it pays workers' medical claims directly out of its own funds instead of buying a fully insured policy from a carrier. That approach saves premium and gives the employer control over plan design, but it exposes the business to an open-ended risk: one premature infant, transplant, or cancer case can generate seven figures of claims. Stop-loss insurance is the reinsurance-style backstop that caps that exposure, reimbursing the employer once claims climb past a defined attachment point.
There are two flavors, and most self-funded plans buy both. Specific (individual) stop-loss reimburses claims on any single covered person above a per-member deductible — for example, everything over $75,000 on one employee in a plan year. Aggregate stop-loss protects the plan as a whole, kicking in when the plan's total claims exceed roughly 120–125% of expected claims for all members combined. Together they convert an unpredictable liability into a budgetable one: the employer knows its worst-case cost equals the two attachment points plus the stop-loss premium. This is functionally the small-employer analog to reinsurance, and it is what makes self-funding viable for companies with as few as 25–50 employees under a level-funded arrangement.
A practical nuance buyers must watch is the contract basis. A "12/12" contract covers only claims incurred and paid within the plan year, while "12/15" or "paid" contracts extend the window to catch run-out claims — a real gap if the plan terminates or switches carriers. Buyers should also confirm there is no aggregating specific deductible or laser (a higher deductible the carrier applies to a known high-cost individual) that quietly shifts risk back onto the employer. Stop-loss keeps a self-funded plan's downside bounded much like a self-insured retention caps exposure in a casualty program.
Real-world scenario
Redwood Millwork Co., a 180-employee cabinet manufacturer in Ohio, moved off its fully-insured group plan to a self-funded health arrangement to control renewal spikes. Because a single catastrophic claim could bankrupt the plan, Redwood bought two layers of stop-loss. Its specific (individual) stop-loss carried a $75,000 deductible per covered member with a $1,000,000 per-member reimbursement limit, priced at $310,000 in annual premium. Its aggregate stop-loss added $42,000 of premium and set an attachment point of $2,850,000 — 125% of the plan's $2,280,000 expected annual claims — bringing combined stop-loss premium to $352,000.
In March, a machinist was diagnosed with leukemia. His treatment ran $640,000 for the year. Redwood's plan paid the first $75,000; the specific stop-loss carrier reimbursed the remaining $565,000, all inside the $1,000,000 limit. Separately, a maternity complication produced a $118,000 claim, of which the plan retained $75,000 and the specific policy reimbursed $43,000. Those two members alone triggered $608,000 in specific reimbursements.
Aggregate stop-loss counts only the claims the plan actually retains — that is, claims net of specific reimbursements — so those recovered dollars are excluded from the aggregate tally. Even so, a heavy flu season and several surgeries pushed Redwood's net retained claims to $3,140,000 by December, $290,000 above the $2,850,000 attachment, and the aggregate carrier reimbursed that $290,000. Gross claims for the year totaled $3,748,000. Without any stop-loss, Redwood would have absorbed the full $3,748,000 against its $2,280,000 budget — a $1,468,000 shortfall that would have wiped out its reserve. Instead, stop-loss recoveries of $898,000 held Redwood's retained claim cost to the $2,850,000 attachment plus $352,000 in premium. At renewal the carrier "lasered" the leukemia claimant to a $200,000 specific deductible, raising his individual retention but sparing the other 179 members from a plan-wide rate shock.
How it affects your premium
Stop-loss premium is driven less by a rate manual and more by the specific health profile of your enrolled group and the retention level you choose. Key cost drivers include:
- Specific deductible level — the lower the per-member deductible (e.g., $50,000 vs. $150,000), the more claims transfer to the carrier and the higher the premium.
- Group demographics and size — age, gender mix, and headcount shape expected claim frequency; smaller groups pay more per life because a single claim swings the whole pool.
- Disclosed high-cost conditions and lasers — known ongoing claimants (dialysis, oncology, hemophilia) drive individual "lasers" or flat premium loads based on projected spend.
- Contract basis (12/12, 24/12, run-in/run-out) — broader incurred-and-paid windows that pick up prior-year claims cost more than a tight 12/12 contract.
- Aggregate corridor — the margin above expected claims (commonly 120–125%) that sets your aggregate limit; a tighter corridor increases premium.
- Plan design and network — richer benefits, weak administrative-services-only claim controls, or a broad network raise projected claims and therefore premium.
- Prior claims experience — 12–24 months of loss history and large-claim reports let underwriters price actual trend rather than manual assumptions.
Common misconceptions
Myth: Stop-loss insurance is health insurance for my employees.
Reality:
Stop-loss is coverage for the employer's plan, not the employees — it reimburses the plan when claims exceed a set deductible. Employees never see it; their benefits come from the self-funded health plan itself.
Myth: Buying stop-loss means my company is no longer taking on real risk.
Reality:
You still fully retain claims below the specific deductible and below the aggregate attachment point — stop-loss caps catastrophic losses much like reinsurance does for an insurer, but the day-to-day claim risk stays with you.
Myth: Stop-loss and a level-funded plan are the same thing.
Reality:
A level-funded plan is a packaged self-funded product that bundles stop-loss, administration, and a fixed monthly payment; standalone stop-loss is just the catastrophic layer you buy separately for a self-funded plan.
Frequently asked questions
What is the difference between specific and aggregate stop-loss?
Specific (individual) stop-loss reimburses claims on any one member above a per-person deductible, while aggregate stop-loss protects the plan when total retained claims for the whole group exceed an aggregate limit set above expected costs. Most self-funded employers buy both.
What is a laser in stop-loss insurance?
A laser is a higher-than-standard specific deductible the carrier assigns to a named high-cost claimant at renewal — for example, moving one member to a $200,000 deductible while the rest of the group stays at $75,000 — so the carrier limits its exposure to a known ongoing condition.
Do I still need stop-loss for a small self-funded group?
Yes — smaller groups are actually more volatile because a single catastrophic claim can blow through the plan's reserve, so specific stop-loss with a modest deductible is essential for employers self-funding below a few hundred lives.
How does stop-loss handle claims from a terminated employee?
Claims incurred while a member was covered are still reimbursable under the contract's incurred/paid terms, and continued coverage such as COBRA continuation keeps that member in the risk pool, so their large claims can still hit both the specific and aggregate layers.
What does the stop-loss contract basis (12/12 or 24/12) mean?
The two numbers describe the incurred period and the paid period for counting claims; a 12/12 contract only covers claims incurred and paid within the year, while a 24/12 or run-in contract picks up claims incurred earlier but paid in the current year, reducing gaps when you switch carriers.
Sources cited
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