# What is aggregate stop-loss insurance? Attachment points, corridors and worked examples.

Source: https://ethosbenefits.com/benefits-101/aggregate-stop-loss
Type: Benefits 101
Topic: Stop-loss insurance
Author: Chelsea Ryckis, Founder and President
Reviewed by: Patrick Ansara, Partner and Director of Client Operations
Publisher: Ethos Benefits
Published: 2025-11-07
Last updated: 2026-11-03
Cite as: "What is aggregate stop-loss insurance?," Ethos Benefits, https://ethosbenefits.com/benefits-101/aggregate-stop-loss, updated 2026-11-03.

**Short answer:** Aggregate stop-loss insurance reimburses a self-funded employer when the plan's total claims for the year pass a group-wide cap called the aggregate attachment point. That cap is usually expected claims times a corridor, such as 125 percent. The employer pays claims up to the cap, and the carrier reimburses the excess.

A self-funded employer pays its employees' health claims from its own funds, so a year with far more claims than expected lands on the company. Aggregate stop-loss insurance puts a ceiling on that total. This page explains how the ceiling is set, how it moves with enrollment, and how it works alongside specific stop-loss, with worked examples.

## What is aggregate stop-loss?

Aggregate stop-loss reimburses the plan when total eligible claims for the whole group pass a set dollar amount during the policy period. That amount is the **aggregate attachment point**. The employer pays claims up to it, and the carrier reimburses eligible claims above it, up to the policy's maximum aggregate benefit.

It is one half of a typical stop-loss package. The other half is **specific stop-loss**, which caps what the plan pays for any one person. For how the two fit together, contract types and lasering, see [how stop-loss insurance works](https://ethosbenefits.com/benefits-101/stop-loss-insurance).

| Feature | Specific stop-loss | Aggregate stop-loss |
| --- | --- | --- |
| What it caps | Claims for one covered person | Total claims for the whole group |
| Attachment point | A fixed dollar amount per person, such as $100,000 | Expected claims times a corridor, such as 125 percent |
| Risk it protects against | A single catastrophic claim | A year with many more claims than expected |
| When it pays | As each large claim is filed and approved | Usually after the policy period ends, unless the contract has accommodation |
| Share of the premium | Usually the larger share | Usually the smaller share, because it is rarely triggered |

## How is the aggregate attachment point set?

The aggregate attachment point is the plan's expected claims multiplied by a **corridor**. The corridor is the buffer the employer agrees to carry above expected claims before the carrier pays.

1. **Expected claims.** The carrier or its underwriter projects what the plan will pay in the policy period, using claims history, enrollment, demographics, plan design and trend. Under the NAIC model act, expected claims are the claims projected to be incurred by the group without stop-loss or other insurance.
2. **Corridor.** A corridor of 125 percent is a common example. The Department of Labor uses it in its own description of stop-loss, describing aggregate coverage of claims that exceed 125 percent of expected claims per plan year. Other corridors, such as 120 or 130 percent, are also offered.
3. **Attachment point.** Expected claims times the corridor.

**Example (illustrative numbers only).** A plan expects $1,000,000 in eligible claims for the year. With a 125 percent corridor, the aggregate attachment point is $1,250,000. If eligible claims reach $1,400,000, aggregate stop-loss reimburses $150,000. If they reach $1,200,000, the plan pays all of it and aggregate stop-loss pays nothing.

A lower corridor protects the plan sooner but costs more. A higher corridor costs less but leaves more of a bad year with the employer, which strains cash flow.

### State minimums

Stop-loss is regulated by the states, and some states limit how low the aggregate attachment point can be set. The NAIC Stop Loss Insurance Model Act bars an aggregate attachment point for groups of 50 or fewer below the greatest of $4,000 per group member, 120 percent of expected claims or $20,000, and for groups of 51 or more below 110 percent of expected claims. States that adopt the model may change those amounts, and many have no minimum, so the rules in the state where the policy is issued are the ones that apply.

## What is the difference between monthly and annual aggregate?

Most aggregate contracts set the attachment point with a **monthly aggregate factor** instead of a single fixed number. The factor is a dollar amount per enrolled employee per month, often split by coverage tier. Each month, enrollment times the factor is added to the running total, and the annual attachment point is the sum at the end of the policy period.

This lets the attachment point follow the size of the group. If enrollment shrinks, expected claims shrink too, and so does the cap.

**Example (illustrative numbers only).** Expected claims are $800 per employee per month. With a 125 percent corridor, the aggregate factor is $1,000 per employee per month.

| Scenario | Calculation | Annual attachment point |
| --- | --- | --- |
| 100 employees all year | 100 x 12 x $1,000 | $1,200,000 |
| 100 employees for 6 months, then 80 for 6 months | (100 x 6 x $1,000) + (80 x 6 x $1,000) | $1,080,000 |

The second group's cap fell by $120,000 because enrollment fell. That protects the employer from being measured against a cap built for a larger group.

"Annual aggregate" usually means the claims are measured once, against the full-year attachment point, at settlement. "Monthly aggregate" can mean either the monthly factor above or a contract that measures claims against the attachment point to date during the year. Read the contract to see which one applies.

## What is a minimum aggregate attachment point?

Because a falling enrollment lowers the attachment point, carriers protect themselves with a **minimum aggregate attachment point**. It is a floor written into the contract, usually calculated from enrollment at the start of the policy period. If enrollment drops sharply, the attachment point cannot fall below that floor.

**Example (illustrative numbers only).** Using the table above, suppose the contract's minimum attachment point is $1,140,000. The enrollment-based figure for the shrinking group was $1,080,000, but the plan's attachment point is the higher number, $1,140,000. The employer pays $60,000 more in claims before aggregate coverage responds than the monthly factor alone would suggest.

Check how the minimum is calculated before binding the policy, especially if layoffs, a sale of a division or another enrollment change is likely during the year.

## What is aggregate accommodation?

**Aggregate accommodation** (sometimes called monthly accommodation or an aggregate advance) is an optional feature that reimburses the plan during the year when paid claims run ahead of the attachment point to date. Without it, annual aggregate is usually reimbursed only after the policy period and its run-out end, which can mean waiting many months for money the plan already spent.

**Example (illustrative numbers only).** The group from the first row of the table has 100 employees and a $1,000 monthly factor. By the end of June, the attachment point to date is $600,000, and the plan has paid $680,000 in eligible claims. With accommodation, the carrier advances $80,000. At year-end settlement, the full-year claims are compared with the full-year attachment point. If later months came in low and the plan never passed the annual attachment point, the advance is repaid or offset.

Accommodation helps cash flow. It does not change how much the policy ultimately covers. It is priced separately, and the terms for repayment differ by carrier.

## How are specific claims excluded from the aggregate?

A large claim is counted only once. Whatever specific stop-loss reimburses is excluded from the claims counted toward the aggregate attachment point, so a high-cost claimant counts toward the aggregate only up to the specific deductible.

**Example (illustrative numbers only).** The specific deductible is $100,000. One member has $400,000 in eligible claims. Specific stop-loss reimburses $300,000, and only the $100,000 the plan paid counts toward the aggregate.

| | Amount |
| --- | --- |
| Total eligible claims paid by the plan | $1,500,000 |
| Less amounts reimbursed under specific stop-loss | ($300,000) |
| Claims counted toward the aggregate | $1,200,000 |

If the aggregate attachment point is $1,250,000, this plan stays under it, even though gross claims were $1,500,000. This is why specific and aggregate coverage are priced and evaluated together. A lower specific deductible also lowers the claims that flow into the aggregate.

Contracts also apply other limits before counting claims toward the aggregate, such as excluded services, lasered amounts and the incurred and paid dates in the contract basis (12/12, 12/15 and so on). Lasered claims in particular can count differently from contract to contract, so ask how they are treated.

## What is an aggregating specific deductible?

An **aggregating specific deductible (ASD)** is an extra layer of claims the plan pays above the specific deductible before specific stop-loss reimburses anything. It applies across all claimants combined. Once the plan has paid claims above the specific deductible equal to the ASD, specific stop-loss reimburses normally for the rest of the policy period.

**Example (illustrative numbers only).** The specific deductible is $100,000 and the ASD is $150,000. Three members pass the specific deductible during the year.

| Member | Claims above $100,000 | Paid by plan toward ASD | Reimbursed by specific stop-loss |
| --- | --- | --- | --- |
| Member A | $80,000 | $80,000 | $0 |
| Member B | $60,000 | $60,000 | $0 |
| Member C | $50,000 | $10,000 | $40,000 |
| **Total** | **$190,000** | **$150,000** | **$40,000** |

Without the ASD, specific stop-loss would have reimbursed all $190,000. With it, the plan keeps $150,000 more risk in exchange for a lower specific premium. Some contracts count ASD amounts toward the aggregate attachment point and some do not, so confirm that before comparing quotes.

An ASD tends to fit employers with steady claims history, strong cash reserves and a clear tolerance for risk. It is a poor fit for groups with frequent large claims, uneven cash flow or a first year of self-funding.

## Pros and cons of aggregate stop-loss.

| Pros | Cons |
| --- | --- |
| Caps total claims for the year, which protects the budget in a bad year | Rarely triggered when the corridor is set at 125 percent or higher, so many years it pays nothing |
| Makes self-funding workable for smaller groups, including [level-funded plans](https://ethosbenefits.com/benefits-101/level-funded-vs-self-funded) | Annual aggregate is usually paid after year end, so the plan carries the cash until settlement |
| Monthly factors let the cap follow enrollment | The minimum attachment point can keep the cap high when enrollment falls |
| Accommodation can smooth cash flow during the year | Accommodation, run-out and terminal liability add cost and contract terms to track |

## Common mistakes to avoid.

- **Buying aggregate without specific.** Aggregate alone leaves the plan exposed to one very large claim up to the aggregate attachment point.
- **Comparing quotes on different terms.** Corridor, contract basis, minimum attachment point, accommodation and laser treatment all change what a quote is worth. Line them up before comparing price.
- **Ignoring the minimum attachment point.** If enrollment may drop, the floor can matter more than the factor.
- **Misreading the timing.** Know when settlement happens and whether accommodation applies, so the plan has the cash to pay claims in the meantime.
- **Forgetting the run-out and terminal liability.** If the plan changes carriers or ends self-funding, claims incurred but not yet paid can fall outside both contracts. See [stop-loss contract types](https://ethosbenefits.com/benefits-101/stop-loss-insurance).
- **Not reviewing at renewal.** Claims trend, enrollment and plan changes all move expected claims. Re-check the corridor and specific deductible every year.

Ethos Benefits reviews and places stop-loss contracts, including aggregate terms, through its [stop-loss service](https://ethosbenefits.com/services/stop-loss).

## From the Ethos Benefits team

> A broker brokers a risk transfer, which is the most expensive function that is their most direct route to compensation.

Donovan Ryckis, Founder and CEO, Ethos Benefits, on The Business of Benefits, Episode 82

## Frequently asked questions

### What is an aggregate attachment point?

The aggregate attachment point is the total amount of eligible claims a self-funded plan pays in a policy period before aggregate stop-loss starts reimbursing. It is usually set as expected claims times a corridor and built up month by month from enrollment, with a contract minimum so it cannot fall too far if enrollment drops.

### What is the difference between aggregate and specific stop-loss?

Specific stop-loss caps what the plan pays for any one person, using a per-person deductible, so it protects against one very large claim. Aggregate stop-loss caps what the plan pays for the whole group in total, so it protects against many mid-sized claims adding up. Most self-funded employers buy both, and amounts reimbursed under specific are excluded from the aggregate.

### Do large individual claims count toward the aggregate attachment point?

Only the part the plan pays. Amounts reimbursed under specific stop-loss are excluded from the aggregate, so a large claim counts toward the aggregate attachment point only up to the specific deductible. That keeps the same dollars from being reimbursed twice, once under each coverage, and it is why the two coverages are priced separately.

### When is aggregate stop-loss paid?

Annual aggregate is usually settled after the policy period and its run-out end, once all of the year's claims have been counted, so the plan carries the overage until then. Some contracts add aggregate accommodation, which reimburses the plan during the year when paid claims run ahead of the attachment point to date.

### Do you need aggregate stop-loss if you have specific stop-loss?

Not always, but most self-funded employers carry both. Specific stop-loss protects against one very large claim, and aggregate protects against many mid-sized claims adding up to a bad year. Larger groups with strong reserves sometimes skip aggregate, while smaller or newer self-funded groups and level-funded plans usually rely on it. No federal law requires either one.

### What corridor do aggregate stop-loss policies use?

The corridor is set in each contract as a percentage of expected claims, so compare it line by line across quotes. Some states limit how low it can go. The NAIC model act, which states may adopt or change, bars aggregate attachment points below 110 percent of expected claims for groups of 51 or more, and sets a higher floor for groups of 50 or fewer.

## Sources

1. [Stop Loss Insurance Model Act (Model](https://content.naic.org/sites/default/files/model-law-092.pdf), National Association of Insurance Commissioners
2. [Technical Release 2014-01: Guidance on State Regulation of Stop-Loss Insurance](https://www.dol.gov/agencies/ebsa/employers-and-advisers/guidance/technical-releases/14-01), U.S. Department of Labor, Employee Benefits Security Administration
3. [Model Law Chart: Stop Loss Insurance Model Act, state adoption](https://content.naic.org/sites/default/files/model-law-chart-ha-90-stop-loss-coverage.pdf), National Association of Insurance Commissioners