Most States Allow Medicaid Managed Care Plans Discretion To Restrict Substance Use Disorder Treatment Benefits.

Managed care plans, which contract with states to cover three-quarters of Medicaid enrollees, play a crucial role in addressing the drug epidemic in the United States. However, substance use disorder benefits vary across Medicaid managed care plans, and it is unclear what role states play in regulating their activities. To address this question, we surveyed thirty-three states and Washington, D.C., regarding their substance use disorder treatment coverage and utilization management requirements for Medicaid managed care plans in 2021. Most states mandated coverage of common forms of substance use disorder treatment and prohibited annual maximums and enrollee cost sharing in managed care. Fewer than one-third of states forbade managed care plans from imposing prior authorization for each treatment service. For most treatment medications, fewer than two-thirds of states prohibited prior authorization, drug testing, "fail first," or psychosocial therapy requirements in managed care. Our findings suggest that many states give managed care plans broad discretion to impose requirements on covered substance use disorder treatments, which may affect access to lifesaving care.

Primary care visit cadence and hospital admissions in high-risk patients.

OBJECTIVES: Most Medicare beneficiaries obtain supplemental insurance or enroll in Medicare Advantage (MA) to protect against potentially high cost sharing in traditional Medicare (TM). We examined changes in Medicare supplemental insurance coverage in the context of MA growth. STUDY DESIGN: Repeated cross-sectional analysis of the Medicare Current Beneficiary Survey from 2005 to 2019. METHODS: We determined whether Medicare beneficiaries 65 years and older were enrolled in MA (without Medicaid), TM without supplemental coverage, TM with employer-sponsored supplemental coverage, TM with Medigap, or Medicaid (in TM or MA). RESULTS: From 2005 to 2019, beneficiaries with TM and supplemental insurance provided by their former (or current) employer declined by approximately half (31.8% to 15.5%) while the share in MA (without Medicaid) more than doubled (13.4% to 35.1%). The decline in supplemental employer-sponsored insurance use was greater for White and for higher-income beneficiaries. Over the same period, beneficiaries in TM without supplemental coverage declined by more than a quarter (13.9% to 10.1%). This decline was largest for Black, Hispanic, and lower-income beneficiaries. CONCLUSIONS: The rapid rise in MA enrollment from 2005 to 2019 was accompanied by substantial changes in supplemental insurance with TM. Our results emphasize the interconnectedness of different insurance choices made by Medicare beneficiaries.

Deductible double jeopardy: patients may pay more out of pocket when pregnancy crosses 2 years.

OBJECTIVES: This study explores the concern that annual high-deductible commercial insurance plan design may yield higher out-of-pocket costs when an episode of maternity care spans 2 years, exposing patients to their cost-sharing limits twice during their episode of care. STUDY DESIGN: Cross-sectional study of Health Care Cost Institute commercial claims. METHODS: The study sample comprises 1,379,300 deliveries among high-deductible health plan enrollees in years 2012 through 2021. Patients' mean cost sharing is calculated across all service types for 3 time periods: (1) delivery hospitalization, (2) maternity episode from 40 weeks prior to delivery hospitalization through 12 weeks after discharge, and (3) extended period spanning 3 years from January of the year before delivery through December of the year after delivery. RESULTS: For each of the 3 episode measurements, mean out-of-pocket spending is highest among those who deliver in January and declines in each subsequent month until August and September (the delivery months with most pregnancy and postpartum periods within the same year), then flattens for the remainder of the year. Mean cost sharing for the maternity episode was $6308 in January and $4998 in December, a difference of $1310. Patients delivering in January also had mean out-of-pocket costs $1491 greater for delivery hospitalization and $1005 greater over the 3-year period than patients delivering in December. CONCLUSIONS: Higher out-of-pocket spending is observed when patients face their cost-sharing limits twice within an episode of maternity care, and this difference persists even when evaluating 3 calendar years of patients' out-of-pocket spending.

Association Between Cost Sharing and Naloxone Prescription Dispensing.

Importance: Increasing access to naloxone (an opioid antagonist that can reverse overdose) could slow the US opioid epidemic. Prior studies suggest cost sharing may be a barrier to dispensing of naloxone prescriptions, but these studies were limited by their cross-sectional designs and use of databases that do not capture prescriptions that are not filled (abandoned). Objective: To evaluate the association between cost sharing and naloxone prescription abandonment (nondispensing of naloxone prescriptions). Design, Setting, and Participants: This cross-sectional, regression discontinuity analysis exploited the fact that deductibles typically reset at the beginning of the year in commercial and Medicare plans. The included data were derived from the 2020-2021 IQVIA Formulary Impact Analyzer (a pharmacy transactions database that represents 63% of prescriptions at US pharmacies). The analysis included claims for naloxone nasal spray among commercially insured patients and Medicare patients that occurred during the 60 days before January 1, 2021, through 59 days after January 1, 2021. Exposure: Cost sharing, which is defined as the amount patients would have to pay to fill prescriptions. Main Outcomes and Measures: Local linear regression models were used to assess for abrupt changes in cost sharing and the probability of prescription abandonment on January 1, 2021. To estimate the association between cost sharing and prescription abandonment, a fuzzy regression discontinuity analysis was conducted. Results: These analyses included naloxone claims for 71 306 commercially insured patients and 101 706 Medicare patients (40 019 [56.1%] and 61 410 [60.4%], respectively, were female). The commercially insured patients and Medicare patients accounted for 73 311 and 106 076 naloxone claims, respectively. On January 1, 2021, the mean cost sharing per claim increased by $15.0 (95% CI, $13.8-$16.2) for commercially insured patients and increased by $12.3 (95% CI, $10.9-$13.6) for Medicare patients and the probability of abandonment increased by 4.7 (95% CI, 3.2-6.2) percentage points and 2.8 (95% CI, 1.6-4.1) percentage points, respectively. The results from the fuzzy regression discontinuity analysis suggest a decision by commercial and Medicare plans to increase naloxone cost sharing by $10 would be associated with percentage-point increases of 3.1 (95% CI, 2.2-4.1) and 2.3 (95% CI, 1.4-3.2), respectively, in the probability of abandonment. Conclusions: The elimination of cost sharing might be associated with increased naloxone dispensing to commercially insured and Medicare patients.

Association of Medicare Advantage Enrollment With Financial Burden of Care : A Retrospective Cohort Study.

BACKGROUND: Compared with traditional Medicare (TM), Medicare Advantage (MA) plans typically offer supplemental benefits and lower copayments for in-network services and must include an out-of-pocket spending limit. OBJECTIVE: To examine whether the financial burden of care decreased for persons switching from TM to MA (TM-to-MA switchers) relative to those remaining in TM (TM stayers). DESIGN: Retrospective longitudinal cohort study comparing changes in financial outcomes between TM-to-MA switchers and TM stayers. SETTING: Population-based. PARTICIPANTS: 7054 TM stayers and 1544 TM-to-MA switchers from the Medical Expenditure Panel Survey, 2014 to 2021. MEASUREMENTS: Individual health care costs (out-of-pocket spending and cost sharing), financial burden (high and catastrophic), and subjective financial hardship (difficulty paying medical bills, paying medical bills over time, and inability to pay medical bills). RESULTS: Compared with TM stayers, TM-to-MA switchers had small differences in out-of-pocket spending ($168 [95% CI, -$133 to $469]) and proportions of total health expenses paid out of pocket (cost sharing) (0.2 percentage point [CI, -1.3 to 1.7 percentage points]), families with out-of-pocket spending greater than 20% of their income (high financial burden) (0.3 percentage point [CI, -2.5 to 3.0 percentage points]), families reporting out-of-pocket spending greater than 40% of their income (catastrophic financial burden) (0.7 percentage point [CI, -0.1 to 1.6 percentage points]), families reporting paying medical bills over time (-0.2 percentage point [CI, -1.7 to 1.4 percentage points]), families having problems paying medical bills (-0.4 percentage point [CI, -2.7 to 1.8 percentage points]), and families reporting being unable to pay medical bills (0.4 percentage point [CI, -1.3 to 2.0 percentage points]). LIMITATION: Inability to account for all medical care and cost needs and variations across MA plans, small baseline differences in out-of-pocket spending, and potential residual confounding. CONCLUSION: Differences in financial outcomes between beneficiaries who switched from TM to MA and those who stayed with TM were small. Differences in financial burden ranged across outcomes and did not have a consistent pattern. PRIMARY FUNDING SOURCE: The National Research Foundation of Korea.

Traditional Medicare supplemental insurance and the rise of Medicare Advantage.

OBJECTIVES: Most Medicare beneficiaries obtain supplemental insurance or enroll in Medicare Advantage (MA) to protect against potentially high cost sharing in traditional Medicare (TM). We examined changes in Medicare supplemental insurance coverage in the context of MA growth. STUDY DESIGN: Repeated cross-sectional analysis of the Medicare Current Beneficiary Survey from 2005 to 2019. METHODS: We determined whether Medicare beneficiaries 65 years and older were enrolled in MA (without Medicaid), TM without supplemental coverage, TM with employer-sponsored supplemental coverage, TM with Medigap, or Medicaid (in TM or MA). RESULTS: From 2005 to 2019, beneficiaries with TM and supplemental insurance provided by their former (or current) employer declined by approximately half (31.8% to 15.5%) while the share in MA (without Medicaid) more than doubled (13.4% to 35.1%). The decline in supplemental employer-sponsored insurance use was greater for White and for higher-income beneficiaries. Over the same period, beneficiaries in TM without supplemental coverage declined by more than a quarter (13.9% to 10.1%). This decline was largest for Black, Hispanic, and lower-income beneficiaries. CONCLUSIONS: The rapid rise in MA enrollment from 2005 to 2019 was accompanied by substantial changes in supplemental insurance with TM. Our results emphasize the interconnectedness of different insurance choices made by Medicare beneficiaries.

Shingles Vaccination in Medicare Part D After Inflation Reduction Act Elimination of Cost Sharing.

This cross-sectional study uses data from retail pharmacies to examine shingles vaccine uptake among Medicare Part D beneficiaries following an IRA policy to eliminate cost sharing.

The impact of terminating cost-sharing reductions payments on health insurance plan choices.

The Trump administration terminated cost-sharing reductions (CSRs) payments to health insurers in 2017, while still required insurers to provide CSRs to eligible enrollees in the Marketplace. Marketplace administration data reveals that, in response to this termination, insurers raised premiums to compensate for their loss. Consequently, premium increases led to more advanced premium tax credits for enrollees in the Marketplace. To investigate the impact of CSRs payment termination on low-income consumer insurance plan choices, I leverage variations in state price regulations and employed a difference-in-differences design. In a robustness analysis, I utilized differences in county income distributions to examine the effects of the termination on insurance choices. The results indicate that after the termination, more low-income enrollees opted for cheaper bronze plans, and fewer chose silver plans. These results suggest that alterations in subsidy channels may inadvertently encourage low-income individuals to purchase less expensive health insurance plans, highlighting an unintended consequence of the termination of cost-sharing subsidies.

Research on collaborative innovation optimization strategies for digitally enabled higher education ecosystems.

Digitally enabled higher education involves the in-depth use of new-generation digital technology, which has subverted and innovated the traditional teaching mode, driven the development of high-quality teaching and learning, and improved teachers' teaching experience, and increased efficiency. Based on ecosystem theory, this paper constructs a higher education ecosystem with the government, enterprises, and universities as the core participating subjects. It considers the participating subjects' effort level and the ecosystem's overall benefits under the three scenarios of noncooperative research and development (R&D), cost sharing, and cooperative R&D. The results show that (1) the service innovation effort level of the three parties increases with increasing human resource level and technology maturity, and the government's benefit decreases with increasing cost of fulfilling social responsibility. (2) The government's cost subsidies to universities and enterprises can enhance the service innovation level of both parties and increase the optimal returns of the three parties and the ecosystem as a whole. (3) In the cooperative R&D game scenario, the effort level of the three parties and the total ecosystem returns are greater than those in the noncollaborative R&D scenario, and after determining the subsidy coefficients of the government, Pareto optimality of the three parties and the ecosystem as a whole can be achieved. The conclusions of this study can aid in understanding the dynamic evolution mechanism of digitally enabled higher education and provide a realistic decision-making reference for higher education ecosystem managers.

PERSPECTIVE: A Path to Value-Based Insurance Design for Mental Health Services.

BACKGROUND: Aligning cost of mental health care with expected clinical and functional benefits of that care would incentivize the delivery of high value treatments and services. In turn, ineffective or untested care could still be offered but at costs high enough to offset the delivery of high value care. AIMS: The authors comment on Benson and Fendrick's paper on Value-Based Insurance Design (VBID) for mental health in the September 2023 special issue of this journal. The authors also present a preliminary framework of key ingredients needed to consider VBID for mental health treatments and services. METHODS: The authors briefly review current and past efforts to contain costs and improve quality of mental health care, which include (for example) use of carve-out and carve-in programs, evaluation of cost sharing models, impact of accountable care organizations, and studying other benefit designs and impact of federal and state policies. RESULTS: Using PTSD as an example, key ingredients of VBID for mental health services were identified and include the following: tools for case identification and monitoring progress over time at the population level; specific treatments and services with evidence of clinical effectiveness, cost-effectiveness, and health equity; and an approach to document the specific treatment or service was delivered (versus another treatment or service that may lack evidence). DISCUSSION: The inability to afford mental health care is a top barrier to treatment seeking. People who do elect to spend time and money on mental health care are further disadvantaged by accessing care that is not well regulated and the quality at best is questionable. VBID could be an important lever for increasing access to and use of high value mental health care. Partnerships among the research, practice, and policy communities can help ensure research solutions meet needs of these two communities. IMPLICATIONS FOR HEALTH CARE: VBID holds promise to make high value mental health care more affordable while discouraging low value treatments and services. IMPLICATIONS FOR HEALTH POLICIES: While evidence gaps remain, these gaps can be filled concurrently with pursuit of VBID for mental health services. IMPLICATIONS FOR FUTURE RESEARCH: This paper identifies important research opportunities to help make VBID a reality for mental health care.

Cost sharing for oral lenvatinib among commercially insured patients.

OBJECTIVE: To use a nationwide pharmaceutical claims database to evaluate cost-sharing trends for commercially insured patients with cancer who were prescribed lenvatinib (Lenvima). STUDY DESIGN: IBM MarketScan databases were used to evaluate lenvatinib costs for patients with employer-based commercial insurance, and for patients 65 years and older, Medicare claims for fee-for-service plans. METHODS: Patients were included if they had least 1 outpatient pharmaceutical claim for lenvatinib paid on a noncapitated basis from 2015 to 2019. Median and IQR costs were estimated and inflation adjusted to 2019 US$ for 30-day supplies and reported as total, insurance liability, coordination of benefits, and out-of-pocket costs. RESULTS: A total of 685 patients had at least 1 pharmaceutical claim for lenvatinib, which included patients with thyroid (n = 251; 36.6%), renal cell (n = 202; 29.5%), hepatocellular (n = 160; 23.4%), and endometrial (n = 48; 7.0%) cancer. The median (IQR) number of prescriptions per patient was 3 (2-7), and the median (IQR) total days of supply was 90 (45-210) days. The median (IQR) 30-day cost of lenvatinib was $17,253 ($15,597-$18,120). Median (IQR) 30-day insurance liability was $16,847 ($15,000-$17,981). Median (IQR) 30-day coordination of benefits was $0 ($0-$0). Median (IQR) 30-day patient out-of-pocket cost was $32 ($0-$100). However, the maximum 30-day out-of-pocket cost in our patient cohort was $12,538. CONCLUSIONS: In this cohort, insurance was liable for the majority of total lenvatinib drug costs, and 75% of patients paid $100 or less per month out of pocket. This information can be used by care teams to counsel insured patients. Health systems and drug manufacturers must identify patients with high out-of-pocket costs and provide convenient access to financial assistance programs so that patients are not forced to forgo the benefits of these drugs due to financial barriers. Value-based payment models and drug pricing reform are also needed to address underlying drivers of high drug costs.

Association of State Insulin Out-of-Pocket Caps With Insulin Cost-Sharing and Use Among Commercially Insured Patients With Diabetes : A Pre-Post Study With a Control Group.

BACKGROUND: Twenty-five states have implemented insulin out-of-pocket (OOP) cost caps, but their effectiveness is uncertain. OBJECTIVE: To examine the effect of state insulin OOP caps on insulin use and OOP costs among commercially insured persons with diabetes. DESIGN: Pre-post study with control group. SETTING: Eight states implementing insulin OOP caps of $25 to $30, $50, or $100 in January 2021, and 17 control states. PARTICIPANTS: Commercially insured persons with diabetes and insulin users younger than 65 years. Subgroups of particular interest included members from states with insulin OOP caps of $25 to $30, enrollees with health savings accounts (HSAs) that require high insulin OOP payments, and lower-income members. MEASUREMENTS: Mean monthly 30-day insulin fills and OOP costs. RESULTS: State insulin caps were not associated with changes in insulin use in the overall population (relative change in fills per month, 1.8% [95% CI, -3.2% to 6.9%]). Insulin users in intervention states saw a 17.4% (CI, -23.9% to -10.9%) relative reduction in insulin OOP costs, largely driven by reductions among HSA enrollees; there was no difference in OOP costs among nonaccount plan members. More generous ($25 to $30) state insulin OOP caps were associated with insulin OOP cost reductions of 40.0% (CI, -62.5% to -17.6%), again primarily driven by a larger reduction in the subgroup with HSA plans. LIMITATIONS: Single national insurer; 9-month follow-up. CONCLUSION: Insulin OOP caps were associated with reduced insulin OOP costs but no overall increases in insulin use. A proposed national insulin cap of $35 for commercially insured persons might lead to meaningful insulin OOP savings but have a limited effect on insulin use. PRIMARY FUNDING SOURCE: Centers for Disease Control and Prevention and National Institute of Diabetes and Digestive and Kidney Diseases.

Effects of nurse visit copayment on primary care use: Do low-income households pay the price?

Nurses are increasingly providing primary care, yet the literature on cost-sharing has paid little attention to nurse visits. We employ a staggered difference-in-differences design to examine the effects of adopting a 10-euro copayment for nurse visits on the use of public primary care among Finnish adults. We find that the copayment reduced nurse visits by 9%-10% during a one-year follow-up. There is heterogeneity by income in absolute terms, but not in relative terms. The spillover effects on general practitioner (GP) use are negative but small, with varying statistical significance. We also analyze the subsequent nationwide abolition of the copayment. However, we refrain from drawing causal conclusions from this due to the lack of credibility in the parallel trends assumption. Overall, our analysis suggests that moderate copayments can create a greater barrier to access for low-income individuals. We also provide an example of using a pre-analysis plan for retrospective observational data.

Evolution analysis of low-carbon cooperation of service providers based on Moran process in cloud manufacturing.

Low-carbon cooperation among cloud manufacturing service providers is one way to achieve carbon peak and neutrality. Such cooperation is related to the benefits to service providers adopting low-carbon strategies and stochastic factors such as government low-carbon policies, providers' environmental awareness, and demanders' low-carbon preferences. Focusing on the evolutionary process of service providers' low-carbon strategy selection under uncertain factors, a stochastic evolutionary game model is constructed based on the Moran process, and the equilibrium conditions for low-carbon cooperation among providers are analyzed under benefit-dominated and stochastic factor-dominated situations. Through numerical simulation, the effects of the cloud platform's cost-sharing coefficient for low-carbon investment, matching growth rate, carbon trading price, and group size on providers' low-carbon strategy evolution are analyzed. The research results show that increasing the cloud platform's low-carbon cost-sharing, carbon trading price, and group size can promote low-carbon cooperation among service providers. With greater low-carbon investment costs and greater stochastic factor interference, the providers' enthusiasm for low-carbon cooperation decreases. This study fills the research gap in the low-carbon cooperation evolution of cloud manufacturing providers based on the stochastic evolutionary game and provides decision-making suggestions for governments and cloud platforms to encourage provider participation in low-carbon cooperation and for providers to adopt low-carbon strategies.

Prescription Drug Dispensing and Patient Costs After Implementation of a No Behavioral Health Cost-Sharing Law.

Importance: On January 1, 2022, New Mexico implemented a No Behavioral Cost-Sharing (NCS) law that eliminated cost-sharing for mental health and substance use disorder (MH/SUD) treatments in plans regulated by the state, potentially reducing a barrier to treatment for MH/SUDs among the commercially insured; however, the outcomes of the law are unknown. Objective: To assess the association of implementation of the NCS with out-of-pocket spending for prescription for drugs primarily used to treat MH/SUDs and monthly volume of dispensed drugs. Design, Settings, and Participants: This retrospective cohort study used a difference-in-differences research design to examine trends in outcomes for New Mexico state employees, a population affected by the NCS, compared with federal employees in New Mexico who were unaffected by NCS. Data were collected on prescription drugs for MH/SUDs dispensed per month between January 2021 and June 2022 for New Mexico patients with a New Mexico state employee health plan and New Mexico patients with a federal employee health plan. Data analysis occurred from December 2022 to January 2024. Exposure: Enrollment in a state employee health plan or federal health plan. Main Outcomes and Measures: The primary outcomes were mean patient out-of-pocket spending per dispensed MH/SUD prescription and the monthly volume of dispensed MH/SUD prescriptions per 1000 employees. A difference-in-differences estimation approach was used. Results: The implementation of the NCS law was associated with a mean (SE) $6.37 ($0.30) reduction (corresponding to an 85.6% decrease) in mean out-of-pocket spending per dispensed MH/SUD medication (95% CI, -$7.00 to -$5.75). The association of implementation of NCS with the volume of prescriptions dispensed was not statistically significant. Conclusions and Relevance: These findings suggest that the implementation of the New Mexico NCS law was successful in lowering out-of-pocket spending on prescription medications for MH/SUDs, but that there was no association of NCS with the volume of medications dispensed in the first 6 months after implementation. A key challenge is to identify policies that protect from high out-of-pocket spending while also promoting access to needed care.

Episode-Based Cost Sharing to Prospectively Guarantee Patients' Out-of-Pocket Costs.

This Viewpoint proposes episode-based cost sharing as a way to prospectively guarantee out-of-pocket costs for patients while also preventing insurers from absorbing cost differentials created by unexpected complications of care.

Health Plan Switching and Health Care Utilization: A Randomized Clinical Trial.

Importance: While the Patient Protection and Affordable Care Act (ACA) helped make health insurance premiums more affordable with premium tax credits, ACA marketplace enrollees continue to face barriers to care. Objective: To investigate the effect of informational emails on plan switching and health care utilization. Design, Setting, and Participants: This randomized clinical trial was conducted during the 2021 special enrollment period in California's Affordable Care Act marketplace among households that reported receiving unemployment insurance and were enrolled in non-silver-tier plans. The trial targeted 42 470 households that became temporarily eligible for cost-sharing reduction (CSR) silver plans that covered 94% of medical costs (CSR silver 94 plans) as a result of the 2021 American Rescue Plan Act. Intervention: Households were randomized to either a no-email control group or to a treatment group receiving 2 informational emails encouraging households to switch to CSR plans. Main Outcomes and Measures: The primary outcome was the switch rate to a CSR silver plan by July 31, 2021. Secondary outcomes include various measures of health care utilization in the second half of 2021 (July 1, 2021, to December 31, 2021). Health care utilization was measured by rates of practitioner visits, emergency department visits, hospitalizations, and prescription fills. Results: Of the 42 470 households (head of household mean [SD], age, 41.4 [13.3] years; 51.7% male), 10 650 (25.1%) were in the control group and 31 820 (74.9%) were in the treatment group. The emails led to a statistically significant 3.1-percentage point (95% CI, 2.6-3.6 percentage points) increase in CSR silver 94 enrollment (a 74.8% relative increase) by July 31, 2021, and a 1.3-percentage point (95% CI, 0.2-2.4 percentage points) increase (a 2.3% relative increase) in practitioner visits by December 31, 2021. The emails had no detectable effect on prescription fills, emergency department visits, or hospitalizations. Conclusions and Relevance: The results of this randomized clinical trial provide experimental evidence that, with access to more affordable health care, individuals are more likely to visit practitioners. Trial Registration: ClinicalTrials.gov Identifier: NCT05891418.

Site of Ambulance Origination and Billing for Out-of-Network Services.

Importance: The No Surprises Act implemented in 2022 aims to protect patients from surprise out-of-network (OON) bills, but it does not include ground ambulance services. Understanding ground ambulance OON and balance billing patterns from previous years could guide legislation aimed to protect patients following ground ambulance use. Objective: To characterize OON billing from ground ambulance services by evaluating whether OON billing risk differs by the site of ambulance origination (home, hospital, nonhospital medical facility, or scene of incident). Design, Setting, and Participants: Cross-sectional study of the Merative MarketScan dataset between January 1, 2015, and December 31, 2020, using claims-based data from employer-based private health insurance plans in the US. Participants included patients who utilized ground ambulances during the study period. Data were analyzed from June to December 2023. Exposure: Medical encounter requiring ground ambulance transportation. Main Outcomes and Measures: Ground ambulance OON billing prevalence was calcuated. Linear probability models adjusted for state-level mixed effects were fit to evaluate OON billing probability across ambulance origins. Secondary outcomes included the allowed payment, patient cost-sharing amounts, and potential balance bills for OON ambulances. Results: Among 2 031 937 ground ambulance services (1 375 977 unique patients) meeting the inclusion and exclusion criteria, 1 072 791 (52.8%) rides transported men, and the mean (SD) patient age was 41 (18) years. Of all services, 1 113 676 (54.8%) were billed OON. OON billing probabilities for ambulances originating from home or scene were higher by 12.0 percentage points (PP) (95% CI, 11.8-12.2 PP; P < .001 for home; 95% CI, 11.7-12.2 PP; P < .001 for scene) vs those originating from hospitals. Mean (SD) total financial burden, including cost-sharing and potential balance bills per ambulance service, was $434.70 ($415.99) per service billed OON vs $132.21 ($244.92) per service billed in-network. Conclusions and Relevance: In this cross-sectional study of over 2 million ground ambulance services, ambulances originating from home, the scene of an incident, and nonhospital medical facilities were more likely to result in OON bills. Legislation is needed to protect patients from surprise billing following use of ground ambulances, more than half of which resulted in OON billing. Future legislation should at minimum offer protections for these subsets of patients often calling for an ambulance in urgent or emergent situations.