Specific vs. Aggregate Stop-Loss (and Lasers), Explained
By the PlanVantage engine teamPublished June 4, 20268 min read
Self-funding a health plan means paying your own claims. Most of the time that is a good trade: the employer keeps the margin a carrier would have priced in, sees its own data, and pays for what actually happens. The exception is the tail. One member's treatment can cost more than the rest of the plan combined, and a heavy claims year does not check the budget first. Stop-loss insurance exists to make those tails survivable, and it comes in two forms that answer two different questions. Specific stop-loss answers: what if one person has a catastrophic year? Aggregate stop-loss answers: what if the whole plan does? This guide covers how each works, how attachment points and corridors set the price, and what it means when the carrier hands you a laser.
What Specific Stop-Loss Covers: The Catastrophic Individual
Specific stop-loss (also called individual stop-loss, or ISL) reimburses the employer once any single member's claims cross a set threshold in the policy year. That threshold is the specific deductible, sometimes called the specific attachment point. Below it, the plan pays. Above it, the stop-loss carrier pays the plan back.
Worked example: A 500-life group buys a $75,000 specific deductible. A premature infant spends fourteen weeks in the NICU and the claims reach $1.2 million. The plan pays the first $75,000 like any other claim. The stop-loss carrier reimburses the remaining $1,125,000. For the employer's budget, a seven-figure event became a $75,000 event.
Mid-market employers commonly buy specific deductibles between $50,000 and $250,000, scaling with group size. There is no formula for picking one: it is a judgment call weighing headcount, the employer's actual risk tolerance, and the premium quoted at each level.
Why specific coverage matters more every year
Sun Life's 2026 high-cost claims report found $1 million-plus stop-loss claims rose 46% in frequency from 2022 to 2026. Segal's SHAPE analysis of 2019–2023 claims found members with claims above $100,000 are fewer than 1% of claimants yet account for roughly 30% of plan spend. Cell and gene therapies now list at seven figures per course. A million-dollar claimant used to be a career event for a benefits manager. It is now an annual planning assumption.
What Aggregate Stop-Loss Covers: The Catastrophic Year
Aggregate stop-loss (ASL) protects against the other failure mode: no single catastrophic claimant, just more claims than expected, everywhere, all year. It reimburses the employer when total plan claims exceed the aggregate attachment point for the year.
Worked example: The underwriter sets expected claims at $6,000,000 with a 125% corridor, so the aggregate attachment is $7,500,000. Claims come in at $7,900,000 with no single member over the specific deductible. The aggregate policy reimburses $400,000. The employer absorbed the first $1,500,000 of adverse experience; the carrier took the rest.
Two mechanics keep the policies honest. First, each member's claims count toward the aggregate only up to the specific deductible, so the two coverages never pay for the same dollar. Second, most aggregate contracts accrue the attachment monthly, and many offer monthly aggregate accommodation: the carrier advances reimbursement mid-year if year-to-date claims run over the accumulated attachment, instead of settling once at year end.
Because a group rarely runs 25% over expected without a catastrophic individual driving it, aggregate coverage is triggered far less often than specific and costs a small fraction of the total stop-loss premium. It is sleep insurance for the CFO, and it is usually priced like it.
Attachment Points and Corridors: The Dials That Set the Price
Stop-loss pricing is a transfer of layers. Every dial moves premium in one direction and retained risk in the other; there is no setting that reduces both.
The specific deductible
Raising the specific from $50,000 to $100,000 cuts premium meaningfully, but the employer now retains every claim in the $50,000–$100,000 layer, and that layer holds the most common large claims. The premium savings are certain; the retained claims are not. Price the layer, not the discount.
The aggregate corridor
A 125% corridor means the employer self-insures the first 25% of adverse experience before the aggregate responds. A tighter 120% corridor costs more; a looser corridor is cheaper and closer to catastrophic-only. The corridor is the deductible of the bad year.
The quiet dial: contract basis
Stop-loss contracts specify when a claim must be incurred and paid to count: 12/12, 12/15, 24/12, or paid. A 12/12 contract stops reimbursing the day the policy year ends, even for care delivered inside it, so late-paying claims from the final months land back on the employer. Carrier changes are where this bites: the outgoing and incoming contracts have to hand off cleanly, and a mismatch strands a window of claims that no policy will pay. Treat the basis as a term to confirm at every placement, and put it beside the premium whenever you compare quotes, and give a takeover a 12/15 basis or a run-in provision to cover the prior year's tail.
The right question at placement is not "which option is cheapest" but "how much claims volatility can this budget absorb before someone has to explain it to the board." That answer, in dollars, picks the attachment points. If the answer is "very little," the better conversation may be whether self-funding fits at all.
What a Laser Is and Why You Get One
A laser is a member-specific exception written into the stop-loss policy: the carrier sets a higher specific deductible for one named individual with a known high-cost condition, while the rest of the group keeps the standard deductible. The name is apt. The carrier is cutting one risk out of the pool with precision.
Worked example
A group renews with a $100,000 specific deductible. One member is mid-course on a specialty therapy with a predictable seven-figure annual cost. The renewal arrives with that member lasered at $500,000. The employer now holds the first $500,000 of that member's claims each year; stop-loss responds only above it. If the therapy runs $1.2 million, the employer's retained cost for that one member went from $100,000 to $500,000: a $400,000 budget item created by one sentence in the policy.
Why do carriers do it? Insurance prices uncertainty, and a known, continuing course of treatment is not uncertain. It is a scheduled cost. The carrier can either spread it across the premium, which shows up as a much larger increase, or isolate it with a laser and quote the rest of the group at closer-to-normal rates.
That is why a laser is not automatically a bad deal. The comparison that matters is the lasered premium plus the expected retained cost under the laser, against the laser-free premium. Carriers price laser-free quotes to cover the same exposure, so sometimes the laser-free option costs more than the laser risk itself. Run both in dollars, with the lasered member's expected claims above the specific deductible as the retained cost.
Contract protections worth buying before you need them
- • No-new-laser provision: the carrier agrees not to add lasers at the next renewal; stronger versions also lock existing lasers so a lasered deductible cannot be raised.
- • Renewal rate cap: a negotiated not-to-exceed increase on the following year's premium, typically sold together with the no-new-laser term.
How a Big Claim Year Moves Next Year's Premium
Stop-loss is annually underwritten. After a large-claim year, the carrier has seen the tail and will reprice it: brokers and stop-loss underwriters commonly report specific premium increases of 20–50% following a significant claimant, and that is before any laser. At that renewal the employer has a short menu, and every item on it moves risk rather than removing it:
Accept the increase
Clean, but the new premium becomes the baseline the next increase compounds from.
Take the laser
Lower premium, concentrated retained risk on one member. Model the triggered case, not just the quoted case.
Raise the specific deductible
Trades premium for a wider retained layer across the whole group, permanently.
Market the case
A competing carrier may see the risk differently, but watch the contract basis gap when switching, and expect the incumbent's claims data to follow you.
Trend makes the arithmetic worse on its own. Surveys published in the summer of 2026 put 2027 medical trend between 9 and 11 percent before plan changes, with PwC at 9.0 percent for the group market and Segal at 9.9 percent for PPO plans, the highest readings in nearly twenty years, and a fixed specific deductible absorbs a growing share of claims every year even when nothing bad happens. More claimants drift across the attachment point, and the premium follows. A flat renewal on an unchanged deductible is quietly a rate decrease for the carrier, so carriers rarely offer one.
The consultant's job is to price the multi-year cost of risk, not the single-year premium: what the program costs in an expected year, and what the retained layer adds in the year the laser triggers. That work starts long before the carrier reports arrive; the renewal season playbook covers where it fits in the calendar.
Key Takeaways
Specific stop-loss caps the cost of one bad member; aggregate caps the cost of one bad year. The attachment points and corridor are dials that trade premium against retained volatility, and the contract basis decides whether the coverage is really there at the edges. A laser is the carrier declining to insure a cost that is no longer uncertain: compare it to the laser-free quote in dollars, and buy the no-new-laser and rate-cap protections in the years you don't need them, because they are not for sale in the years you do.
Model it before you sign it: PlanVantage Projections carries specific and aggregate stop-loss, lasers and the retained layer each one creates, and a deductible change through the renewal projection, with the actuarial math running live as you work. See it on your own renewal.