Medical Stop-Loss Insurance Cost 2026: A Practical PEPM Guide for Self-Funded Employers

What you are actually buying with stop-loss

When an employer running a self-funded health plan buys stop-loss, what they are really buying is a firewall against unpredictable catastrophic claims. Hold onto that sentence, because it explains everything else about how these contracts are priced and structured.

My read, after seeing plenty of these renewals go sideways: the moment you compare stop-loss quotes on PEPM alone, you have already half-lost. Two quotes at $100 per employee per month can carry completely different real risk depending on the contract basis, the laser language, and whether a specialty drug has been carved out. Stop-loss is a product where “on what terms” matters far more than “how much.”

This is a practical guide for US employers, HR and benefits leaders, and brokers who run or are considering a self-funded plan. We will walk through how self-funding works, how specific and aggregate stop-loss differ, how contract structure moves the price, and how to choose among fully-insured, level-funded, and self-funded.

One thing up front. Stop-loss is not health insurance for your employees. It does not pay their medical bills. The plan (the employer) pays the claims, and stop-loss reimburses the employer only for the excess it could not reasonably absorb. It is insurance for the employer, not for the member.

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How does self-funding work, and why is stop-loss needed?

In a fully-insured arrangement, the employer pays a fixed premium to a carrier and the carrier takes all the claims risk. Whether claims run high or low, the premium is set, and any margin belongs to the carrier.

Self-funding flips that. The employer pays employees’ medical claims out of its own funds, pays a third-party administrator (TPA) an ASO fee to process those claims, and keeps the savings in a good year. Direct control of cash flow and claims data is the real draw. Self-funded plans are also governed by ERISA, which exempts them from most state insurance mandates and premium taxes.

The problem is the tail. If one member incurs a catastrophic claim, a micro-preemie in the NICU, an organ transplant, CAR-T cancer therapy, or a multimillion-dollar gene therapy, a self-funded employer is on the hook for the full amount. For a mid-sized company, that single claim can be existential.

That is where stop-loss enters. Stop-loss is reinsurance-style protection that caps the employer’s risk at a chosen threshold (the attachment point) and shifts everything above it to the stop-loss carrier. It lets the employer keep the upside of self-funding while shearing off the catastrophic downside.

The logic is the same one behind other employer risk tools. Just as key person life insurance transfers the financial shock of losing a critical employee, and business liability insurance transfers the risk of a large third-party claim, stop-loss cherry-picks the tail risk the company cannot absorb and moves it off the balance sheet.

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Specific vs aggregate stop-loss: what actually differs?

There are two kinds of stop-loss, and most self-funded plans buy both, because they do very different jobs.

Specific (individual) stop-loss protects against one large claimant. If a single member’s claims exceed the specific attachment point (say $50,000) in the plan year, the stop-loss carrier reimburses the excess. If one member has a $2 million transplant, the employer pays the first $50,000 and stop-loss covers the remaining $1.95 million.

Aggregate stop-loss protects against a bad year in the aggregate, the case where a lot of ordinary sub-attachment claims pile up higher than expected. The aggregate attachment is usually set at about 125% of expected annual claims (the corridor), and if total plan claims blow past that line, stop-loss reimburses the overage.

Feature	Specific stop-loss	Aggregate stop-loss
Protects against	One catastrophic claimant	Total plan claims running over
Attachment basis	Per-member deductible	Expected claims × corridor (~125%)
Typical attachment	$25K–$500K+ by group size	120–125% of expected claims
How often it triggers	Often, if a big claimant exists	Relatively rare
Share of PEPM cost	Most of the stop-loss spend	Comparatively cheap
Risk if you skip it	One member sinks the company	A bad year busts the budget

In practice, specific stop-loss is the bulk of the stop-loss spend, and aggregate is a relatively inexpensive backstop. The smaller the group, the more a single claim moves the whole plan, so where you set the specific attachment is the decision that matters most.

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Attachment points and lasering: the two levers that move cost

Raise the attachment point and the premium falls. Moving the specific attachment from $50,000 to $100,000 widens the band the employer self-insures, and the stop-loss PEPM drops noticeably. Lower the attachment and the premium climbs. The trick is to calculate, coldly, the maximum retention the company’s cash flow can actually survive in a bad year, and set the attachment there. Set it too low and stop-loss gets nearly as expensive as fully-insured. Set it too high and a bad year blows a hole in liquidity.

Lasering is the trap that catches first-time self-funders. A carrier assigns a much higher individual attachment to a specific known high-cost claimant. Everyone is at $50,000, but the one member on hemophilia therapy gets “lasered” at $400,000, meaning the employer eats that member’s first $400,000.

Lasers bite hardest at renewal. A carrier may quote a clean rate in year one, then, once a large claimant surfaces, laser that person at renewal and send the effective cost soaring. The defenses are a no-new-laser provision and a renewal rate cap. Contracts with these protections cost more, but think of them as insurance on your insurance.

This is exactly why the cheapest quote is often the most dangerous. A low-ball contract with no laser protection looks cheap in year one, then comes back at an unaffordable renewal the moment a large claim hits. The dynamic rhymes with what happens when a policy denies a non-covered claim: the sticker premium tells you almost nothing until you read the conditions under which you actually get stuck paying.

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Why do 12/12, 12/15, and 24/12 change the price?

The two numbers in a stop-loss “contract basis” define which claims are eligible. The first number is the window in which a claim must be incurred; the second is the window in which it must be paid.

US medical claims have a lag between the date of service (incurred) and the date the claim is actually paid. So a claim incurred at the end of the plan year is often paid early the next year. How the contract handles that lag is the contract basis, and it flows straight into the price.

Contract basis	Incurred in	Paid in	Character	Relative cost
12/12	12 months	12 months	Incurred and paid within the year (paid basis)	Cheapest
12/15	12 months	15 months	3-month run-out for lag claims	Middle
12/18	12 months	18 months	6-month run-out	Higher
24/12	24 months	12 months	Includes prior 12 months incurred (run-in)	Useful when converting
Paid	Any incurred	All paid in the year	Whatever is paid this year	Best for mature plans

12/12 (or a pure paid contract) is the cheapest, but a claim incurred late in the year and paid the following year can fall outside protection. 12/15 and 12/18 extend the paid window to catch those tail claims, costing more but safer. 24/12 is useful when moving from fully-insured to self-funded for the first time, because it covers claims incurred before the switch but not yet paid (run-in), sealing the gap during the transition.

That introduces run-in and run-out. Run-in is a new contract covering claims incurred before it started; run-out is a prior contract covering claims paid after it ended. When a company starts or stops self-funding, mishandling this lets claims slip through the crack between two contracts, and the employer swallows them whole. The contract basis hides behind the PEPM number, but it decides the actual quality of the risk transfer.

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What drives stop-loss cost?

Stop-loss rates are not standardized the way fully-insured premiums are. Carriers underwrite each group’s real risk, so two groups of the same size can get very different quotes. The main cost drivers:

Cost driver	Effect on rate	Why it matters
Group size	Smaller means more per-head volatility	One large claim hits a small group harder
Demographics (age, sex)	Older or skewed groups cost more	Drives expected claim frequency and severity
Industry (SIC code)	Higher-risk industries cost more	Manufacturing, construction, healthcare
Plan design	Richer plans cost more	Low member cost-share, broad coverage
Prior claims history	Large-claim history raises rates	The core of underwriting
Known high-cost claimants	Lasers or rate loads	Ongoing severe or chronic cases
Geography	High-cost regions cost more	Hospital pricing and network differences
Attachment level	Higher attachment lowers rate	Wider employer retention band
Specialty and gene-therapy exposure	Upward pressure	Multimillion-dollar claim trend

The biggest structural force pushing rates up in recent years is the arrival of ultra-high-cost claims. Multimillion-dollar gene and cell therapies, new oncology drugs, and specialty medications for chronic disease have led carriers to load specific stop-loss rates aggressively, or to carve specific drugs out of coverage entirely. When you review a renewal, check hard for a drug carve-out slipped into the terms, because a carved-out claim lands entirely on the employer.

Worth adding: stop-loss underwriting is tied to who actually stays on the plan. When a departing worker faces a coverage gap after leaving a job and continues on the plan through COBRA, that member’s claims feed back into your stop-loss experience. A shift in your workforce mix is a shift in your rate.

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Fully-insured vs level-funded vs self-funded: which do you choose?

The real menu an employer faces is three options. Stop-loss only touches the self-funded family (and its level-funded cousin).

Feature	Fully-insured	Level-funded	Self-funded + stop-loss
Who holds the risk	Carrier	Employer (but capped)	Employer (up to attachment)
Monthly payment	Fixed premium	Fixed monthly (admin + stop-loss + reserve)	Admin + actual claims + stop-loss
When claims run low	Carrier keeps it	Partial surplus refund possible	Employer keeps the savings
Predictability	Very high	High (capped)	Moderate (attachment is the cap)
Data access	Limited	Reporting provided	Full claims data
Best fit size	Any size	10–150 employees	100+ (small via level-funded)
ERISA governed	Partly	Yes	Yes

Fully-insured is the simplest and most predictable, but the carrier keeps the good years and your data access is thin. Self-funded is the opposite: you control the data and cash flow and keep the upside, but you carry the risk and the administrative load. Level-funded sits in between, a hybrid that keeps the predictability of a fixed monthly payment while giving smaller groups the benefits of self-funding, including a partial surplus refund when claims come in low.

For a sense of cost, here are PEPM ranges (they swing widely by group):

• Specific stop-loss: commonly $40–$150+ PEPM. Low attachments ($25K–$50K) and older groups push toward the top; high attachments ($150K+) and younger groups toward the bottom.
• Aggregate stop-loss: commonly $5–$20 PEPM, far cheaper than specific.
• Admin (ASO/TPA) fee: commonly $25–$60 PEPM, varying with network and add-on services.

Treat these as a starting point, not a quote. Actual rates depend on underwriting. Because self-funding is a decision to retain business risk yourself, it starts with the same discipline as sorting out disability insurance versus workers’ comp: draw a clear line between which risks the company will carry and which it will transfer.

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Common mistakes and a stop-loss checklist

The mistakes I see repeatedly:

One, comparing PEPM only. The most common and most expensive error. The lowest quote often lacks no-new-laser protection, uses a 12/12 basis, or carves out a drug. Compare the full contract, not the headline rate.

Two, ignoring the contract basis. Missing a 24/12 or 12/15 in the first year leaves the claims-lag window uninsured, which is brutal in the first year converting from fully-insured.

Three, setting the attachment untethered from cash flow. The attachment should equal the most the company can truly absorb in a bad year. Chasing a lower premium with an attachment you cannot survive turns a claim spike into a liquidity crisis.

Four, not negotiating no-new-laser and a rate cap. Whether these exist decides your real cost in years two and three. The renewal structure often matters more than the first-year rate.

Five, ignoring specialty and gene-therapy exposure. Miss a drug carve-out slipped into the renewal and the moment an employee needs that drug, millions become the employer’s problem.

Six, blurring the interests of broker, TPA, and stop-loss carrier. When the TPA that adjudicates claims differs from the carrier that reinsures them, disputes over whether a claim is stop-loss eligible can leave the employer caught in the middle.

As a checklist: contract basis (including run-in and run-out), no-new-laser language, renewal rate cap, cash-flow fit of both attachments, drug carve-outs, and alignment between the TPA and the stop-loss carrier. Confirm those six and you can see the real quality of a stop-loss contract. When you design the broader benefits budget, it also helps to weigh tools like key person coverage alongside it as part of overall capital allocation.

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Related reading

• 👉 Business Liability Insurance Cost 2026: General, Professional, and Product Liability
• 👉 Disability Insurance vs Workers’ Comp 2026
• 👉 Health Insurance After Quitting a Job 2026
• 👉 Key Person Life Insurance 2026

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This article is for general informational purposes only and does not recommend any specific insurance product or provide insurance, tax, or legal advice for any particular company. Stop-loss and self-funding decisions depend heavily on a company’s finances, workforce mix, and claims history, so before entering any contract you should obtain a review from a qualified insurance broker, actuary, and tax or legal professional. The PEPM and rate ranges shown are illustrative of general market tendencies and do not guarantee any specific quote.