What Stop Loss Insurance Means in Health Care

Stop loss insurance is a type of coverage that protects employers and health plans from extremely high medical bills

Stop loss insurance works like a safety net. When an employee or member of a health plan runs up medical costs that exceed a certain dollar amount in a year, stop loss insurance kicks in and covers the rest. The employer or health plan stops paying out of pocket once that threshold is reached — hence the name "stop loss."

This is different from the health insurance that covers your doctor visits and prescriptions. Stop loss is a separate policy that protects the organization offering the health plan, not the individual patient. It exists because one person's catastrophic illness — a cancer diagnosis, a major accident, a chronic condition requiring expensive treatment — can cost a health plan hundreds of thousands of dollars in a single year.

Key Takeaways

• Stop loss insurance protects employers and health plans when one person's medical costs become very high, not individual patients.
• There are two main types: individual stop loss (covering one person's costs above a threshold) and aggregate stop loss (covering all employees' costs combined above a threshold).
• The threshold amount varies by employer size and plan design, and is set when the policy is purchased.
• Stop loss insurance is purchased by the employer or health plan administrator, not by individual workers or patients.
• This coverage does not change what you pay out of pocket — your deductible, copay, and coinsurance stay the same.

How the threshold works

When an employer buys stop loss insurance, they choose a threshold amount — often called the "attachment point" or "deductible." This might be $50,000 per person per year, or $500,000 for all employees combined. The exact number depends on the size of the employer, how many people are in the plan, and how much risk the employer wants to carry themselves.

Once one person's medical bills hit that threshold, the stop loss insurer begins paying the rest of that person's claims for the rest of the year. If an employee has $200,000 in cancer treatment and the individual stop loss threshold is $50,000, the stop loss insurer covers the $150,000 above the threshold. The employer still pays the first $50,000.

For aggregate stop loss, the math works across the entire employee group. If the threshold is $500,000 total and all employees' medical claims add up to $750,000 in a year, the stop loss insurer covers the $250,000 above the threshold.

Individual stop loss versus aggregate stop loss

Individual stop loss protects against one person's catastrophic costs. It has a per-person threshold — say, $75,000. If one employee's medical bills exceed $75,000 in a year, the stop loss insurer covers the overage. This protects the employer from being wiped out by a single serious illness.

Aggregate stop loss protects against the total cost of all claims in the plan. It has a threshold for the entire group — say, $2 million. If all employees' medical bills combined exceed $2 million in a year, the stop loss insurer covers the overage. This protects the employer from an unusually expensive year overall, even if no single person has catastrophic costs.

Many employers buy both types. Individual stop loss handles the worst-case scenario for one person. Aggregate stop loss handles the scenario where many people have moderate claims that add up to more than expected.

Who buys stop loss insurance and why

Large employers with hundreds or thousands of employees often self-insure — meaning they pay their employees' medical claims directly instead of buying traditional health insurance. For these employers, stop loss insurance is essential. Without it, one employee's $500,000 cancer treatment could drain the entire benefits budget.

Smaller employers sometimes buy stop loss insurance too, especially if they want to self-insure part of their health plan costs. A mid-size employer might buy traditional health insurance for routine care but add stop loss coverage to protect against claims above a certain amount.

Health insurance companies and health plans also buy stop loss insurance to protect themselves. When a health plan covers millions of people, even a small percentage of catastrophic cases can add up. Stop loss insurance spreads that risk across multiple insurers.

Stop loss insurance does not change what you pay

If your employer has stop loss insurance, you will not see it on your pay stub or your insurance card. It does not affect your deductible, copay, or coinsurance. Your out-of-pocket costs remain exactly the same whether or not your employer has this coverage.

Stop loss is invisible to employees because it is a business-to-business transaction. Your employer negotiates the stop loss policy with an insurance company, just as they negotiate the health plan itself. The coverage protects the employer's finances, not your personal medical costs.

If you have a very expensive medical event, you still pay your deductible and coinsurance as usual. The stop loss insurer reimburses your employer for the costs above the threshold, not you directly.

How stop loss premiums are calculated

The cost of stop loss insurance depends on several factors: the size of the employee group, the age and health profile of the employees, the geographic location, and the threshold amount chosen. A lower threshold (more protection) costs more in premiums. A higher threshold (less protection) costs less.

Insurers also look at claims history. If a company has had very high claims in the past, the stop loss premium will be higher. If claims have been stable and moderate, the premium will be lower. Some employers get a discount if they have good wellness programs or safety records.

Stop loss premiums are typically paid quarterly or annually by the employer. The cost is a business expense and is not passed directly to employees, though it is factored into the overall cost of the health plan.

Frequently Asked Questions

Does stop loss insurance cover me as an employee?

No. Stop loss insurance protects your employer or health plan, not you personally. It reimburses your employer for costs above the threshold, but it does not change what you pay out of pocket. Your regular health insurance coverage is what protects you.

What happens if my medical bills exceed the stop loss threshold?

The stop loss insurer begins paying the employer's share of your claims above the threshold. You continue to pay your deductible, copay, and coinsurance as normal. The stop loss payment goes to your employer, not to you or your provider.

Can I buy stop loss insurance for myself?

No. Stop loss insurance is sold only to employers and health plans, not to individuals. If you are looking for personal protection against high medical costs, you would look at your health insurance plan's out-of-pocket maximum, which is the most you will pay in a year.

Why would an employer choose a high stop loss threshold instead of a low one?

A high threshold means lower premiums but more risk for the employer. A small employer might choose a high threshold to save money on premiums, betting that no single employee will have catastrophic costs. A large employer might choose a low threshold to protect against any major claim.

Is stop loss insurance the same as reinsurance?

They are similar but not identical. Reinsurance is insurance that insurance companies buy to protect themselves. Stop loss is a specific type of reinsurance that protects against high individual or aggregate claims. All stop loss is reinsurance, but not all reinsurance is stop loss.