High-cost claims are the largest driver of volatility and long-term expense in employer-sponsored health plans. While routine primary care visits and generic prescriptions add up, a single catastrophic claim, often exceeding $100,000, can destabilize a self-funded employer's budget and inflate premium rates for fully insured groups. National health spending data from KFF show that the top 5% of people by health spending accounted for about half of all spending in 2022. Understanding the true impact of these claims is essential for employers who want to control costs without sacrificing quality care.
The financial effect of high-cost claims extends far beyond the claim payment itself. For self-funded employers, a few large claims can trigger higher stop-loss insurance premiums, increased administrative fees, and unpredictable cash flow. For fully insured employers, these claims are averaged into the community pool, but a heavy year of high-cost events among a group can still lead to substantial premium hikes at renewal. The ripple effects include reduced profitability, pressure to shift costs to employees, and even the risk of having to abandon self-funding due to reinsurance constraints.
What qualifies as a high-cost claim?
While definitions vary, high-cost claims are generally those exceeding $50,000 to $100,000 in a single plan year. That floor has drifted upward as treatment costs have climbed: a 2025 WTW survey found that claims once considered high-cost at $50,000 now often start at $100,000, and some carriers define high-cost claimants as members with more than $100,000 in annual paid claims. The most common sources include:
- Cancer treatments (especially immunotherapy and CAR-T cell therapy)
- Neonatal intensive care (premature or high-risk newborns)
- Organ transplants (kidney, liver, heart, or bone marrow)
- Spinal surgeries and joint replacements with complications
- Inpatient mental health or substance use disorder stays
- Gene therapies and advanced specialty pharmaceuticals (e.g., for rare diseases)
Direct and indirect cost impacts on employers
1. Premium rate escalation
For fully insured employers, high-cost claims in a group's experience can cause the carrier to re-rate the group at renewal. In many states, carriers apply experience rating to groups above 50 employees, which means a heavy claim year feeds directly into the next rate calculation and pushes the increase above the underlying medical trend. This creates a higher baseline that persists for years.
2. Stop-loss insurance premiums
Self-funded employers purchase stop-loss coverage to cap individual claim liability. Each high-cost claim that approaches or exceeds the stop-loss attachment point (e.g., $100,000 or $250,000) signals risk to the reinsurer. The result is a higher stop-loss premium at renewal, often with more restrictive exclusions or higher deductibles for specific conditions like cancer or transplants.
3. Cash flow unpredictability
High-cost claims create lumpy spending patterns. A small employer with 50 employees might see cash reserves drained by a single $200,000 hospital stay. This unpredictability forces organizations to maintain larger cash reserves, borrow funds, or seek alternative financing, all of which carry hidden costs in time and opportunity.
4. Employee cost-sharing adjustments
Employers often offset rising claim costs by increasing deductibles, copays, or out-of-pocket maximums. While this reduces the employer's direct spend, it can decrease plan participation, worsen care compliance, and lead to higher emergency utilization. In the long run, underinsurance can increase the frequency of high-cost claims due to delayed care.
5. Wellness program ROI erosion
When a small cohort of participants drives a disproportionate share of spending, the returns on broad wellness initiatives (e.g., biometric screenings, gym reimbursements) may appear diminished. Employers may mistakenly cut wellness investments, ignoring that these programs prevent lower-cost chronic conditions from escalating into catastrophic events.
Strategies to mitigate the impact of high-cost claims
Proactive employers manage the risk before and after high-cost claims occur. Evidence-based approaches include:
- Implement care navigation programs: Guide members with serious diagnoses to centers of excellence, where complication rates and total cost of care run lower. A RAND study of three surgical procedures found that a bundled-payments program reduced total surgery costs by an average of $4,229, a 10.7% relative reduction.
- Use stop-loss coverage wisely: Analyze historical claims to set appropriate attachment points. Consider using a level-funded plan or a captive arrangement for mid-size groups to gain more control over reinsurance costs.
- Use specialty pharmacy management: Review high-cost drug utilization, mandate step therapy, and negotiate rebates through a pharmacy benefit manager (PBM). For gene therapies, explore carve-out arrangements or manufacturer-sponsored outcomes-based contracts.
- Focus on case management and advocacy: Assign a dedicated nurse navigator to every high-cost claimant. Timely discharge planning, medication adherence support, and coordination with palliative care can reduce avoidable readmissions and shorten length of stay.
- Model risk with data analytics: Use predictive analytics to identify members likely to develop high-cost conditions (e.g., pre-diabetes with no treatment). Target interventions like disease management or telehealth coaching before claims spiral.
Million-dollar claims are becoming more common
The risk profile behind high-cost claims is shifting. Anthem's claims data show that the number of claims over $1 million jumped nearly 74% between 2021 and 2024. Gene and cell therapies sit at the center of this change. CAR-T therapies carry list prices between $300,000 and $600,000. That price is only the start. Once hospital stays and side-effect management are added, total cost of care can exceed $1 million for a single patient.
Employers that once treated a seven-figure claim as a rare shock now budget for them as recurring events. For self-funded groups, this changes the stop-loss math: attachment points that looked generous five years ago may no longer cover the full spread of a gene therapy claim, and reinsurers are pricing accordingly. Groups that review their specific and aggregate attachment points each year, and that plan for specialty pharmacy spend separately, are better positioned than those that treat million-dollar claims as outliers.
Prevention through population health management
The most effective way to manage high-cost claims is to prevent them. Employers that invest in a population health strategy, including affordable preventive care, mental health support, and chronic disease management, reduce the incidence of catastrophic events. Even a small reduction in the number of claims over $100,000 can yield substantial net savings that directly improve the bottom line. In the current health benefits environment, high-cost claims are data points to study and systematically mitigate.
High-cost claims magnify employer healthcare costs through direct payments, insurance premium adjustments, and operational unpredictability. Targeted mitigation tactics, combined with upstream health improvement, let employers protect their finances while delivering better outcomes for their most vulnerable employees.