Growing bipartisan support has fueled awareness and proposals to protect patients from “surprise” bills—bills where a patient unintentionally receives care from an out-of-network provider. While there is a growing literature on surprise bills from emergency and out-of-network providers at in-network hospitals, less is known regarding surprise bills resulting from visits to office-based clinicians.

An outpatient surprise bill may result from the complexities of provider network participation (e.g., a provider may be in-network at one location but not another) or inconsistent procedures and communication between patients and office staff. Outdated provider directory listings can mislead patients to believe an out-of-network provider is in-network. Yet patients are still responsible for increased out-of-network costs. In addition to higher cost-sharing and the balance bill, patients may have no out-of-network coverage or have separate (and higher) out-of-network deductibles and maximums. In a 2018 national internet survey, we assessed the proportion of privately insured patients that received outpatient surprise bills, experiences with provider directories, and whether patients obtained reimbursement from their insurer.


Survey participants were recruited through KnowledgePanel.1 This internet panel consists of ~ 55,000 households and is constructed using high-quality probability-based sampling methods. The survey completion rate was 66%. Weights were applied to match the sample to the US population and adjust for panel recruitment, oversampling, and nonresponse. The NYU School of Medicine and Yale Institutional Review Boards approved the study and participants were consented. The survey oversampled those using out-of-network care and allowed for a detailed description of experiences with up to two out-of-network general medical providers. Experiences with mental health providers were previously reported and thus omitted from these analyses.2 A participant was considered to have received a “surprise” bill if they became aware a provider was out-of-network at the first appointment or when they received the bill.


Our sample included 1148 privately insured adults ages 18–64 that used outpatient general healthcare in the prior year. Participants were predominately white (69%), female (54%), and ages 50–64 years (43%) (Table 1). Overall, 3% (N = 207) received at least one surprise outpatient bill in the last year. Those with fair or poor self-reported health were significantly more likely to experience surprise bills. Twelve percent noted that a provider listed in their insurance directory had either incorrect contact information or did not take their insurance. The proportion was significantly higher among those receiving surprise bills (30%).

Table 1 Associations of Surprise Bills with Demographic Characteristics and Report of Directory Errors

Of visits to out-of-network providers (N = 654), 39% were associated with surprise bills. Most out-of-network visits (70%) were not reimbursed by the insurer, with no out-of-network coverage and an unmet deductible being the most commonly cited reasons (Table 2). Surprise bills were no more likely to come from specialists compared with primary care providers.

Table 2 Characteristics of Outpatient Out-of-Network Providers


Among outpatient visits to out-of-network providers, 39% were associated with surprise bills, representing 3% of privately insured. Educational level and income were not associated with receiving a surprise bill, suggesting that system-level failures rather than patient health literacy are driving this problem. While patients are reasonably expected to confirm that the provider accepts their insurance before an office visit, providers—or their office staff—have a role in discussing network participation before care is delivered.

Similar to previous literature for Medicare Advantage, Medicaid managed care, and some Marketplace plans,3, 4 directory errors were commonly reported by our privately insured sample, and 30% of those reporting an outpatient surprise bill noted an error. Previously proposed federal legislation required that enrollees in private plans have access to accurate directories and are protected from costs related to directory errors.5 Other proposed remedies include increasing provider engagement and accountability for directory information and advancing directory data technology.

Limitations of this study include the use of self-report and other possible biases inherent in internet surveys, although non-response bias was mitigated through weighting. The prevalence of outpatient surprise bills may vary by market and plan and our study did not allow us to identify these differences. Also, because our data are cross-sectional, we were unable to establish causal effects.

Provider networks are an important tool if they give plans leverage when negotiating prices with providers and result in lower premiums.6 Yet, if patients cannot accurately identify in-network providers, networks may unfairly lead to surprise bills and increase patient out-of-pocket costs.