A medical stop-loss captive is a group self-funding arrangement where multiple employers — typically 10 to 50 companies — pool their stop-loss layer rather than buying individual stop-loss coverage from a commercial carrier. Each employer self-funds its own claims up to a specific deductible. Above that threshold, claims flow into the captive pool shared by all members. When the pool performs well collectively, members share in the underwriting profit rather than the commercial carrier keeping it. It delivers the transparency and data ownership of self-funding with the risk-smoothing benefit of pooling with other good-risk employers.

In a fully-insured plan, your premiums are pooled with every other employer in the carrier’s risk pool — good claims years and bad ones alike. The carrier keeps the underwriting profit when claims run low. In a captive, you self-fund your base claims layer, buy stop-loss through the captive pool alongside other vetted employers, and participate in surplus returns when the pool performs well. You own your claims data, control plan design, and are exempt from most state insurance mandates and premium taxes. The fundamental difference: in a fully-insured plan the carrier wins when you have a good year; in a captive, you do.

Most medical stop-loss captives are designed for employers with 50 to 500 employees, though some programs accept smaller or larger groups depending on structure. The more important criteria are claims history and risk profile — captives are selective about membership precisely because good-risk employers are the product. Employers with stable workforces, reasonable claims histories, and a willingness to engage in wellness and utilization management are the strongest candidates. We run a readiness analysis before recommending any captive program — group size is just one factor.

The primary risk is adverse pool performance — if the captive’s collective claims exceed projections in a given year, members may be assessed additional contributions or see reduced surplus returns. Unlike a fully-insured plan where the carrier absorbs all variance, captive members share in both the upside and the downside of pool performance. Most well-structured captives carry aggregate stop-loss protection on the pool itself to cap worst-case exposure. There is also a collateral or letter-of-credit requirement in most programs — a cash deposit the employer provides as security. Understanding the collateral structure, aggregate protection, and exit terms before joining is essential, and something we walk through in detail with every client.

Yes, but exit terms vary by program and should be reviewed carefully before joining. Most captives have a run-out period — typically 12 months after exit — during which the employer remains financially responsible for claims incurred while they were a member but not yet paid. Some programs have minimum participation commitments of two to three years. Collateral held during membership is generally returned after the run-out period clears. We review exit provisions in detail as part of every captive evaluation — a program with restrictive or punitive exit terms is a signal worth paying attention to.

When the captive pool’s aggregate claims come in below the funded level, the surplus is distributed to members — typically after a lag of 12 to 18 months to allow claims run-out to settle. Distribution formulas vary by program: some allocate proportionally to each member’s premium contribution, others use more complex risk-adjusted allocations. Surplus returns are one of the most financially meaningful differences between captive and fully-insured arrangements — in a good claims year, returns can be substantial. In a fully-insured plan, that money stays with the carrier. We model expected surplus scenarios for each client as part of the captive evaluation.

Medical stop-loss captives are typically structured as self-funded ERISA plans at the employer level, which means the base health plan is generally exempt from state insurance mandates and premium taxes — the same structural advantage as traditional self-funding. The captive entity itself is domiciled in a specific state or offshore jurisdiction and subject to the regulatory requirements of that domicile. The combination of federal ERISA preemption at the plan level and captive domicile regulation at the entity level creates a flexible but compliance-intensive structure. We work with experienced ERISA and captive counsel on every engagement to ensure regulatory posture is properly addressed.

We start with a readiness analysis — claims history, workforce profile, risk tolerance, and financial capacity — before recommending any program. Not every employer is a good captive candidate, and we’re direct about that. When a captive makes sense, we evaluate multiple programs against each other: pool composition and underwriting standards, stop-loss carrier quality, collateral requirements, surplus distribution history, exit terms, and administrative capabilities. We don’t represent a single captive program — we evaluate the market and recommend the structure that fits the employer. After placement, we manage the ongoing relationship including open enrollment, compliance, annual performance reviews, and renewal strategy.

Most captive placements take 90 to 120 days from initial analysis through effective date. The timeline includes readiness assessment, program evaluation and selection, underwriting submission and approval, collateral arrangement, plan document drafting, TPA setup, and open enrollment. Captive underwriting is more rigorous than standard stop-loss — the program needs to assess your claims history and risk profile before accepting membership. Starting the process at least 90 days before your renewal date is strongly recommended. Rushing the underwriting or due diligence phase is one of the most common mistakes employers make when evaluating captives.