Out-of-network (OON) charges are one of the most volatile and poorly controlled cost drivers in employer-sponsored health plans. Unlike in-network care, where rates are negotiated in advance and anchored to a percentage of Medicare or a fee schedule, out-of-network providers have no contractual obligation to accept a plan's allowed amount. This creates a direct pipeline for excessive billing, balance billing, and surprise charges that can raise the cost of affected claims well above negotiated rates and, left unchecked, destabilize the entire plan's budget.
The Mechanics: How Out-of-Network Charges Bypass Cost Controls
To understand the cost impact, it's essential to distinguish the three layers of an OON charge. First, the provider's billed charge is an unregulated sticker price, often 300-800% of Medicare. Second, the plan's allowed amount (the maximum it will recognize for reimbursement) is typically based on a "reasonable and customary" (R&C) database, a multiple of Medicare, or a reference-based price. Third, any difference between the billed charge and the allowed amount becomes the member's balance bill, unless prohibited by state law or the federal No Surprises Act for certain emergency and non-emergency services at in-network facilities. Even negotiated in-network hospital prices averaged 254% of what Medicare would pay in 2022, according to RAND, and out-of-network billed charges run far above that.
For employers, the most immediate effect is that even a small volume of OON claims can produce disproportionate costs. Because plans often reimburse OON care at a lower coinsurance rate (e.g., 50% of the allowed amount instead of 80% in-network), the plan's liability might technically be lower per service than in-network. However, the absence of a network discount means the allowed amount itself is far higher, erasing any plan savings and exposing the employee to large balance bills. When the plan has an out-of-network deductible and out-of-pocket maximum, large claims can quickly reach stop-loss thresholds, transferring the cost back to the employer through higher stop-loss premiums or direct claim liability for self-funded plans.
Direct and Indirect Cost Leakage
Out-of-network care affects employer costs through several channels, many of which are hidden in aggregate data:
- Elevated Allowed Amounts: A single OON surgical episode can cost several times the in-network contracted rate for the identical procedure, and even a modest share of OON utilization lifts total medical claims.
- Balance Billing Fallout: While balance bills technically fall on the employee, employers frequently face pressure to intervene, whether through appeals, assistance programs, or one-time concessions, which consumes administrative resources and can set costly precedents. In some cases, employers directly reimburse portions of balance bills to protect talent, turning an unplanned expense into a direct cost.
- Outlier Claims and Stop-Loss Erosion: Self-insured employers rely on stop-loss insurance to cap catastrophic claims. OON bills for air ambulance transports, out-of-network emergency surgery, and specialty drugs administered in an OON facility can run far above typical claim sizes; air ambulance transports alone carry median charges between $36,000 and $40,000, according to the National Association of Insurance Commissioners. Carriers respond by increasing specific and aggregate attachment points, raising premiums at renewal, or inserting OON-specific exclusions.
- Plan Leakage and Adverse Selection: When a plan's network is narrow or reimbursement is perceived as weak, providers may choose to remain OON. This drives members who need those services to seek care OON, creating a cycle of higher utilization and cost. Over time, healthier members may migrate to competitors with broader networks, leaving the plan with a risk pool skewed toward high claimants, further driving up per-member costs.
The No Surprises Act: A Partial Shield with New Employer Obligations
The federal No Surprises Act (effective 2022) eliminated balance billing for out-of-network emergency services, non-emergency services provided by OON practitioners at in-network facilities, and air ambulances. While this protects employees, it shifts the payment dispute to a federal independent dispute resolution (IDR) process between the plan and the provider. For employers, this is a double-edged sword:
- Positively, it removes large, unpredictable balance bills from the member's plate and sets a structured negotiation framework, with the member's cost-sharing based on the qualifying payment amount (QPA), a figure tied to the median in-network contracted rate.
- Negatively, the IDR process can still yield awards well above Medicare rates, and the administrative burden of participating in disputes, tracking QPAs, responding to batched disputes, and paying IDR fees, has added new fixed and variable costs. The law also does not apply to ground ambulance services, and repeated court rulings in the Texas Medical Association cases have forced regulators to pause and restart the IDR process several times, contributing to a backlog of disputes.
In August 2024, the Fifth Circuit vacated the rule that told arbitrators to give presumptive weight to the QPA, and regulators have kept revising the IDR fee and batching rules in response to later rulings. For budgeting, employers can no longer assume OON payments will track older reasonable-and-customary formulas; they must model the QPA and a range of possible IDR outcomes that keeps shifting with each court decision.
Ground Ambulance: The Gap That Remains
The No Surprises Act's largest remaining hole is ground ambulance transport. Air ambulance bills are protected, but ground ambulances are not. A Peterson-KFF Health System Tracker analysis found that about half of emergency ground ambulance transports by people with private insurance result in a potential out-of-network bill. The federal Advisory Committee on Ground Ambulance and Patient Billing approved recommendations for federal protections in the fall of 2023, but Congress has not yet enacted them. State law is the current backstop: New York barred out-of-network balance billing for emergency ambulance services in 2015, and a patchwork of other states has since followed.
For employers, the gap carries real budget risk. Ground ambulance trips happen under emergency conditions, so members cannot shop for an in-network provider, and the balance bill falls on the member when the plan treats the transport as out of network. Employers can reduce this exposure by confirming how their plan reimburses ground ambulance services, checking whether state law limits or bars ambulance balance billing, and pressing their administrator to contract directly with high-volume ground ambulance providers.
Strategic Cost Mitigation: From Passive Payer to Active Purchaser
Progressive employers are no longer treating OON claims as an inevitable leakage. Instead, they are redesigning plans and deploying technology to neutralize the cost effect:
1. Reference-Based Pricing (RBP) with Member Protections
Rather than relying on R&C databases, self-funded plans are setting allowed amounts at a multiple of Medicare (e.g., 140-200% of Medicare) for both in- and out-of-network services. When paired with strong member advocacy services and balance bill negotiation, this approach can cut OON facility and professional claim costs. The key is coupling RBP with a no-balance-bill guarantee or aggressive legal defense fund to shield employees, converting what would be a chaotic OON experience into a controlled, predictable payment model.
2. Strengthening Network Adequacy and Narrow Networks
A common root cause of OON usage is a network that fails to meet member needs. Employers should conduct advanced network adequacy analyses, looking at appointment wait times, specialty coverage, and geographic access, not just directory counts. By contracting with a high-performance narrow network or a center of excellence, employers can reduce OON reliance while negotiating stronger discounts, eliminating the OON premium for planned care.
3. Plan Design Incentives and Transparency Tools
Many plans inadvertently encourage OON use by offering out-of-network benefits at all. Evidence shows that removing OON coverage for non-emergency services (except where state mandates require it) and combining that with real-time cost-comparison tools can drive down OON utilization. If full removal is too aggressive, implementing a separate, higher OON deductible and out-of-pocket maximum, along with mandatory pre-service disclosure of estimated costs and balance billing risks, shifts member behavior toward in-network providers.
4. Data-Driven Audit and Recovery
Out-of-network claims are fertile ground for overbilling, unbundling, and upcoding. Employers using specialized claims integrity vendors that audit OON facility and professional claims before payment can identify inflated charges and negotiate them down retroactively. The savings from such audits routinely exceed the fees paid for them.
Fiduciary and Compliance Considerations
Under ERISA, plan sponsors have a fiduciary duty to ensure that plan assets are used solely for the benefit of participants and that plan expenses are reasonable. Allowing uncontrolled OON leakage may, in extreme cases, be viewed as a breach of that duty, particularly if the plan fails to implement available cost-management tools. The Department of Labor has signaled increased attention to health plan fiduciary practices, including provider network oversight and payment integrity. Employers should document their rationale for OON benefit design, demonstrate competitive bidding for network and cost-containment vendors, and monitor OON trends quarterly as part of their fiduciary governance process.
Quantifying Exposure and Taking Control
The effect of out-of-network charges on employer healthcare costs is a systemic inefficiency that inflates premiums, exposes members to financial harm, and erodes the plan's competitive position. Employers that quantify their OON exposure and implement a multi-pronged strategy combining network optimization, reference-based pricing, aggressive plan design, and data transparency can expect to reduce overall per-employee health costs while improving the member experience. Ignoring OON charges means subsidizing a billing model that profits from the absence of negotiated rates.
This article is for general information only and is not legal, tax, or medical advice. Employers should consult their own advisors.