Download now (opens a new window)The medical stop loss market is experiencing heightened volatility, leaving many employers questioning whether traditional structures still serve their long-term interests. Despite ample capacity, pricing has become less predictable, transparency has eroded, and employers with better risk profiles are increasingly exposed to market strains beyond their control. Organizations with scale and sophisticated risk management practices are increasingly reassessing how medical risk is financed. And for many, captive insurers have emerged as a strategic tool to help offer greater cost stability and control.
A difficult market, even for disciplined employers
Stop loss capacity has outpaced premium growth, putting pressure on underwriting margins. Competition is so intense that premium is spread too thin to keep pace with severity.
Ordinarily, that would favor employers, but today, it’s not translating into better outcomes.
Across the market, medical loss ratios have deteriorated, leaving many carriers operating at or near a loss. In response, carriers have increased pricing. Rather than reflecting individual employer experience, carriers are pushing broad trend increases across their portfolios. Even employers with strong claims performance are being bundled with poorer-performing risks.
The result: Employers with favorable risk profiles are absorbing the financial strain created elsewhere in carrier books. Instead of being rewarded for disciplined plan management and favorable experience, they’re exposed to volatility driven by the broader market.
That dynamic has made renewals more unpredictable. Employers are facing sharper premium increases year over year, wider swings in terms and conditions, and less transparency around how pricing decisions are made. Increasingly, employers — particularly those with scale, strong governance, or existing captives — are asking more strategic questions: Is our risk being priced fairly? Are there better ways to smooth volatility over time? And should this risk be structured differently?
These employers are often finding better answers to these questions in captive insurers.
A strategic alternative: captive insurance
A captive insurer is an insurance company owned and controlled by the organization or organizations it insures. A single-parent captive is owned and controlled by a single organization; companies can also work together to form group captives to collectively underwrite their risks.
Many employers already use single-parent captives to manage property, casualty, and financial risks. Those same structures can, in the right circumstances, be extended to medical stop loss.
For employers reassessing their stop loss strategy, existing captives offer a meaningful advantage: lower friction. The fundamentals are already in place — governance, capital, regulatory approvals, and a functioning business plan — so organizations do not start from scratch. That makes it far easier to evaluate whether medical stop loss belongs within the broader risk framework and to do so deliberately rather than reactively.
Established governance is a critical differentiator. A captive with an experienced board, clear decision-making processes, and sufficient surplus supports realistic expectations around medical risk, which behaves very differently from long-tail property and casualty lines. Existing capital also provides a buffer against volatility, reducing pressure to overpromise short-term financial upside and enabling a more measured, long-term approach.
Just as important, medical stop loss should not be evaluated in isolation. Most employers with captives already look at risk holistically. Adding medical stop loss allows leaders to view total organizational risk in one place, align funding strategies, improve risk distribution, and coordinate more effectively with reinsurance partners who already understand the captive’s risk profile.
That said, adding medical stop loss to a captive is not a cure‑all. It will not always reduce costs in any given year. The primary benefits are greater cost stability, reduced exposure to market volatility, and less cross‑subsidization of poorer risks — outcomes that materialize over time, when the strategy is used as intended.
Realizing success
Employers can generally use captives for medical stop loss in three distinct ways:
1. To improve risk distribution and support tax qualification.
Some captives struggle to meet Internal Revenue Service standards for risk distribution, which is required for a captive to be treated as an insurance company for tax purposes. Medical stop loss — particularly an individual stop loss buy‑down — can be an effective solution. Most auditors view each covered employee in group health programs as a separate insured life. That allows stop loss premiums flowing through a captive to be treated as third‑party risk, improving risk distribution without requiring the captive to take on unaffiliated or pooled risks that are harder to control.
2. To utilize excess surplus and manage volatility more deliberately.
An employer with a well‑capitalized captive may choose to write certain stop loss layers into the captive as a way to put surplus to work. Instead of extracting surplus through dividends — which may trigger tax penalties — the captive uses that capital to absorb a defined layer of medical volatility.
The goal here is not underwriting profit, but greater stability and alignment between medical risk and an organization’s broader risk financing strategy.
3. To issue stop loss through the captive and purchase reinsurance above it.
In a more advanced structure, a captive issues stop loss coverage and then purchases reinsurance above it. This approach — best-suited for sophisticated employers with strong governance, quality, data, and long-term views — can provide access to more favorable pricing, customized terms, and reinsurers who prefer underwriting individual, well‑governed risks rather than large carrier portfolios.
Who can benefit from a single-parent captive?
Writing medical stop loss via a captive is not the right solution for every organization. This strategy works best for employers with existing captives that already write multiple property and casualty lines, such as workers’ compensation, liability, or property. These organizations often can manage medical risk without treating it as a standalone experiment.
Scale also matters. Generally, employers with 2,000 or more covered lives are better positioned to withstand volatility and produce credible experience for underwriting and modeling.
Employers with mature risk management and financial leadership understand that medical stop loss is not a profit center play but a long-term risk financing decision — and that benefits will emerge over time, beyond a single renewal cycle.
Who may not benefit from a single-parent captive?
In contrast, employers focused exclusively on stop loss for employee benefits, with little broader risk management infrastructure, often struggle to make this work. Employers looking for immediate year one wins often become disappointed, even when the strategy is working as designed. Other organizations that may not benefit from this approach include:
White‑collar organizations with minimal property and casualty risk, which may lack the necessary foundation to justify captive expansion for medical stop loss alone.
Fast‑growing companies, especially those expanding through acquisitions, which can face distorted historical experience if modeling isn’t updated appropriately.
Moving forward
As employers navigate a more volatile medical stop loss market, moving forward via captives requires discipline, alignment, and a long‑term view.
The first step is setting clear expectations. Organizations that oversell upside often encounter disappointment later. The real value lies in stability, transparency, and greater control over risk.
Equally important is assessing readiness, not just feasibility. While modeling and actuarial analysis may indicate that alternative structures are possible, readiness depends on governance, data quality, capital strength, and organizational risk tolerance. Employers that move forward before these elements are in place may face internal resistance or unintended volatility that undermines the strategy.
Alignment across the organization is essential and must start at the top. Successful approaches are typically led by the CFO or broader C‑suite, with risk management, finance, HR, and legal teams actively engaged. Medical stop loss often resides within HR, while captives and enterprise risk decisions sit elsewhere. Bridging that divide early helps ensure shared understanding and sustained support.
Employers should also commit to realistic timelines. Education, internal alignment, and strategy development often take longer than execution itself. Allowing sufficient time to build consensus reduces the likelihood of rushed decisions that can compromise results.
Finally, it’s important to choose the right advisor. Ultimately, medical stop loss should be treated as part of a holistic risk strategy — integrated across risk management, benefits, finance, and governance. Viewed this way, it becomes a long‑term tool for navigating market volatility rather than a reactive response to a difficult renewal. Choosing an advisor who can align these disciplines and guide decisions with that long‑term perspective is critical to achieving lasting value.
How Lockton can help
Captives offer multiple pathways for managing medical stop loss — but success depends on clarity of purpose. These strategies work best when aligned to specific objectives and as part of a broader, more holistic strategy.
Lockton can help employers pursue this holistic strategy through our ability to bring property and casualty insurance, employee benefits, captive consulting, and reinsurance together in a coordinated way. At Lockton, our stop loss practice, captive advisory teams, and Lockton Re work in parallel, using the same data and aligned underwriting assumptions. That coordination allows employers to evaluate traditional stop loss, captive strategies, and reinsurance structures simultaneously, rather than in isolation.
For more information or for help, contact a member of your Lockton team.