Segal published its Q3 2026 Trends Focus on stop-loss insurance in August 2026, drawing on data from 225 self-funded health plans in its national medical stop-loss dataset. The headline figure is striking: the number of plan members generating claims above $1 million has grown at an average of 25 percent per year over the last four years. But the more structural finding is the gap that growth rate has opened between fixed attachment points and the claim population those attachment points were priced to absorb.
Average specific stop-loss premiums increased 12.7 percent in Q3 2026 for groups maintaining similar coverage, up from 9.7 percent in the prior period. Across all groups including those adjusting deductibles, the increase was 11.5 percent, up from 7.3 percent. Both figures confirm a continuing hardening trend in the specific stop-loss market. Neither comes close to 25 percent.
The math a CFO should run
A plan that experienced two $1 million-plus claims per year in 2022 should now project approximately four to five per year at the same enrollment size, applying the 25 percent compound annual growth rate over four years. (Two claims compounded at 25 percent annually for four years yields approximately 4.9.) That near-tripling of expected specific stop-loss events is not offset by the premium increases Segal reports. A 12.7 percent annual premium increase compounds to roughly 60 percent over four years; a 25 percent annual claim frequency increase compounds to roughly 144 percent over the same period.
The gap means stop-loss carriers have absorbed part of the excess claim cost through their own loss ratios. That absorption is a temporary condition, not a structural one. At each renewal, carriers reprice the risk into new premiums and may impose attachment point floors that prevent plans from maintaining the same deductible level. Plans that have not raised their specific deductible at each renewal have been retaining a growing share of a growing risk without recognizing it in their reserve estimates.
Where this shows up in your reserves
For self-funded health plan actuarial opinions, the critical variable is the expected frequency of specific stop-loss recoveries in the IBNR calculation. An actuary estimating the plan’s liability above the specific deductible needs a realistic expected number of events that will pierce that threshold during the plan year. If the frequency assumption was calibrated using experience from 2021 or 2022, when seven-figure claims were genuinely uncommon, the expected cost to the plan above the deductible is understated.
The effect runs in two directions. First, the expected loss ratio above the specific deductible is higher than pre-2022 history suggests. This directly raises the plan’s estimated IBNR for the benefit year. Second, the aggregate stop-loss corridor is at greater risk of exhaustion. Aggregate stop-loss covers cumulative plan losses above a corridor, usually expressed as a percentage of expected claims. If the expected claim base is underestimated because high-cost events are more frequent than assumed, the probability of piercing the aggregate attachment rises. Plans with aggregate coverage that has not been recalibrated since 2022 may be carrying an inaccurate picture of aggregate adequacy.
The reserve diagnostic is specific: look at the expected frequency of individual claim recoveries in your actuarial report and ask whether that number reflects experience after January 2022, or a longer historical average anchored in years when seven-figure claims were rare. If the plan has already experienced three $1 million-plus claims in one benefit year against an assumption of two, the assumption needs updating before the next actuarial period closes. The mechanics of this adjustment are covered in IBNR for Self-Funded Health Plans.
Who it affects
Self-insured employers of all sizes who carry specific stop-loss are the primary audience. The Segal data covers 225 plans, a diverse national sample; the frequency growth is not concentrated in large national employers. Plans with stable or declining enrollment are particularly exposed because the growth cannot be attributed to adding members. The claim incidence per member is rising, driven by specialty drug launches and expanded indications, gene and cell therapies carrying per-treatment costs exceeding $3.5 million for some conditions, and new biologics replacing lower-cost therapeutic alternatives.
Captive structures writing stop-loss reinsurance for self-funded employer groups face the same exposure. Single-parent captives using the stop-loss layer as a risk-financing tool need the same frequency update in their own reserving. For how attachment point selection interacts with confidence level and surplus requirements in a captive structure, see Captive Funding at a Confidence Level.
This is consistent with what Sun Life’s 2026 high-cost claims report found: orthopedic and musculoskeletal conditions have entered the top three high-cost categories, expanding the universe of seven-figure events well beyond the gene-therapy and oncology bucket that has historically dominated stop-loss discussion. The frequency growth Segal measures reflects multiple conditions and drug categories, not a single outlier therapy driving one anomalous year.
What this means for your next review
The 25 percent compound annual growth rate in seven-figure claimants is a published benchmark drawn from 225 plans. If your actuarial opinion does not reflect claim frequency assumptions updated since 2022, the expected cost above the specific deductible is likely understated. This does not require waiting for the next annual actuarial review. A mid-year update to the expected frequency assumption is appropriate when the underlying claim environment has demonstrably shifted, and Segal’s dataset provides the basis for that adjustment.
Plans whose premiums have been rising at 12 percent or less while their seven-figure claim frequency has been compounding at 25 percent are accumulating an unrecognized reserve gap. The stop-loss carrier will close that gap at renewal through pricing, attachment point adjustments, or both. The CFO’s job is to close it on the reserve side before the carrier forces the conversation.
Decision-maker checklist
- Ask your actuary whether the expected frequency of $1 million-plus specific stop-loss recoveries in your current opinion was derived from post-2022 experience, or from a longer historical average that includes years when seven-figure claims were uncommon.
- Request a sensitivity analysis showing how IBNR changes if the assumed frequency of specific recoveries increases by 50 percent. This approximates two additional years of 25 percent compound growth from a 2024 baseline.
- Confirm whether your aggregate stop-loss corridor was priced on an expected claim base that reflects current per-member cost trends, not a 2021 or 2022 baseline.
- If the plan has already experienced three or more $1 million-plus claims in the current benefit year, notify your stop-loss carrier promptly to comply with any advance reporting requirements; late notification can void specific recovery rights.
- Ask your TPA whether specialty drug and gene therapy authorizations are flagged as open high-cost exposures in real time, so the reserve picture at any interim date reflects known pending costs above the deductible.
An independent reserve review brings a second pair of eyes that is free of the TPA’s or fronting carrier’s incentive structure. We are working on a directory of independent reviewing actuaries. If you would like to be considered, get in touch.