Association of Evaluation and Management Payment Policy Changes With Medicare Payment to Physicians by Specialty.

Importance: US primary care physicians (PCPs) have lower mean incomes than specialists, likely contributing to workforce shortages. In 2021, the Centers for Medicare & Medicaid Services increased payment for evaluation and management (E/M) services and relaxed documentation requirements. These changes may have reduced the gap between primary care and specialist payment. Objectives: To simulate the effect of the E/M payment policy change on total Medicare physician payments while holding volume constant and to compare these simulated changes with observed changes in total Medicare payments and E/M coding intensity, before (July-December 2020) and after (July-December 2021) the E/M payment policy change. Design, Setting, and Participants: Retrospective observational study of US office-based physicians who were in specialties with 5000 or more physicians billing Medicare and who had 50 or more fee-for-service Medicare visits before and after the E/M payment policy change. Exposures: E/M payment policy changes. Main Outcomes and Measures: Outcomes included physician-level simulated volume-constant payment change, total observed Medicare payment change, and share of high-intensity (ie, level 4 or 5) E/M visits before and after the E/M payment policy change. For each specialty, the median change in each outcome was reported. The payment gap between primary care and specialty physicians was calculated as the difference between total Medicare payments to the median primary care and median specialty physician. Results: The study population included 180 624 physicians. Repricing 2020 services yielded a simulated volume-constant payment change ranging from a 3.3% (-$4557.0) decrease for the median radiologist to an 11.0% ($3683.1) increase for the median family practice physician. After the E/M payment change, the median high-intensity share of E/M visits increased for physicians of nearly all specialties, ranging from a -4.4 percentage point increase (dermatology) to a 17.8 percentage point increase (psychiatry). The median change in total Medicare payments by specialty ranged from -4.2% (-$1782.9) for general surgery to 12.1% ($3746.9) for family practice. From July-December 2020 to July-December 2021, the payment gap between the median primary care physician and the median specialist shrank by $825.1, from $40 259.8 to $39 434.7 (primary care, $41 193.3 in July-December 2020 and $45 962.4 in July-December 2021; specialist, $81 453.1 in July-December 2020 and $85 397.1 in July-December 2021)-a relative decrease of 2.0%. Conclusions and Relevance: Among US office-based physicians receiving Medicare payments in 2020 and 2021, E/M payment policy changes were associated with changes in Medicare payment by specialty, although the payment gap between primary care physicians and specialists decreased only modestly. The findings may have been influenced by the COVID-19 pandemic, and further research in subsequent years is needed.

Organization and Performance of US Health Systems.

Importance: Health systems play a central role in the delivery of health care, but relatively little is known about these organizations and their performance. Objective: To (1) identify and describe health systems in the United States; (2) assess differences between physicians and hospitals in and outside of health systems; and (3) compare quality and cost of care delivered by physicians and hospitals in and outside of health systems. Evidence Review: Health systems were defined as groups of commonly owned or managed entities that included at least 1 general acute care hospital, 10 primary care physicians, and 50 total physicians located within a single hospital referral region. They were identified using Centers for Medicare & Medicaid Services administrative data, Internal Revenue Service filings, Medicare and commercial claims, and other data. Health systems were categorized as academic, public, large for-profit, large nonprofit, or other private systems. Quality of preventive care, chronic disease management, patient experience, low-value care, mortality, hospital readmissions, and spending were assessed for Medicare beneficiaries attributed to system and nonsystem physicians. Prices for physician and hospital services and total spending were assessed in 2018 commercial claims data. Outcomes were adjusted for patient characteristics and geographic area. Findings: A total of 580 health systems were identified and varied greatly in size. Systems accounted for 40% of physicians and 84% of general acute care hospital beds and delivered primary care to 41% of traditional Medicare beneficiaries. Academic and large nonprofit systems accounted for a majority of system physicians (80%) and system hospital beds (64%). System hospitals were larger than nonsystem hospitals (67% vs 23% with >100 beds), as were system physician practices (74% vs 12% with >100 physicians). Performance on measures of preventive care, clinical quality, and patient experience was modestly higher for health system physicians and hospitals than for nonsystem physicians and hospitals. Prices paid to health system physicians and hospitals were significantly higher than prices paid to nonsystem physicians and hospitals (12%-26% higher for physician services, 31% for hospital services). Adjusting for practice size attenuated health systems differences on quality measures, but price differences for small and medium practices remained large. Conclusions and Relevance: In 2018, health system physicians and hospitals delivered a large portion of medical services. Performance on clinical quality and patient experience measures was marginally better in systems but spending and prices were substantially higher. This was especially true for small practices. Small quality differentials combined with large price differentials suggests that health systems have not, on average, realized their potential for better care at equal or lower cost.

Health Care Spending, Utilization, and Quality 8 Years into Global Payment.

BACKGROUND: Population-based global payment gives health care providers a spending target for the care of a defined group of patients. We examined changes in spending, utilization, and quality through 8 years of the Alternative Quality Contract (AQC) of Blue Cross Blue Shield (BCBS) of Massachusetts, a population-based payment model that includes financial rewards and penalties (two-sided risk). METHODS: Using a difference-in-differences method to analyze data from 2006 through 2016, we compared spending among enrollees whose physician organizations entered the AQC starting in 2009 with spending among privately insured enrollees in control states. We examined quantities of sentinel services using an analogous approach. We then compared process and outcome quality measures with averages in New England and the United States. RESULTS: During the 8-year post-intervention period from 2009 to 2016, the increase in the average annual medical spending on claims for the enrollees in organizations that entered the AQC in 2009 was $461 lower per enrollee than spending in the control states (P<0.001), an 11.7% relative savings on claims. Savings on claims were driven in the early years by lower prices and in the later years by lower utilization of services, including use of laboratory testing, certain imaging tests, and emergency department visits. Most quality measures of processes and outcomes improved more in the AQC cohorts than they did in New England and the nation in unadjusted analyses. Savings were generally larger among subpopulations that were enrolled longer. Enrollees of organizations that entered the AQC in 2010, 2011, and 2012 had medical claims savings of 11.9%, 6.9%, and 2.3%, respectively, by 2016. The savings for the 2012 cohort were statistically less precise than those for the other cohorts. In the later years of the initial AQC cohorts and across the years of the later-entry cohorts, the savings on claims exceeded incentive payments, which included quality bonuses and providers' share of the savings below spending targets. CONCLUSIONS: During the first 8 years after its introduction, the BCBS population-based payment model was associated with slower growth in medical spending on claims, resulting in savings that over time began to exceed incentive payments. Unadjusted measures of quality under this model were higher than or similar to average regional and national quality measures. (Funded by the National Institutes of Health.).

Initial Opioid Prescriptions among U.S. Commercially Insured Patients, 2012-2017.

BACKGROUND: The United States is undergoing a crippling opioid epidemic, spurred in part by overuse of prescription opioids by adults 25 to 64 years of age. Of concern are long-duration and high-dose initial prescriptions, which place the patients and their friends and relatives at heightened risk for long-term opioid use, misuse, overdose, and death. METHODS: We estimated the incidence of initial opioid prescriptions in each month between July 2012 and December 2017 using administrative-claims data from across the United States (accessed through Blue Cross-Blue Shield [BCBS] Axis); monthly incidence was estimated as the percentage of enrollees who received an initial opioid prescription among those who had not used opioids (i.e., no opioid prescription or a diagnosis of opioid use disorder in the 6 months before a given month). We then estimated the percentage of enrollees initiating opioid therapy who received a long-duration or high-dose initial opioid prescription in each month during this period. We also calculated the number of providers who initiated opioid therapy in any patient who had not used opioids in each month and examined monthly trends in the duration and dose of initial opioid prescriptions in prescriber and patient subgroups. Our study sample included 63,817,512 enrollees who had not used opioids (mean, 15,897,673 per month). RESULTS: The monthly incidence of initial opioid prescriptions among enrollees who had not used opioids declined by 54%, from 1.63% in July 2012 to 0.75% in December 2017. This decline was accompanied by a decreasing number of providers (from 114,043 in July 2012 to 80,462 in December 2017) who initiated opioid therapy in any patient who had not used opioids. Nonetheless, among the shrinking subgroup of physicians who initiated opioid therapy in such patients, high-risk prescribing (i.e., prescriptions for more than a 3-day supply or for a dose of 50 morphine milligram equivalents per day or higher) persisted at a monthly rate of 115,378 prescriptions per 15,897,673 enrollees who had not used opioids. CONCLUSIONS: As the opioid crisis progressed between July 2012 and December 2017, many providers stopped initiating opioid therapy. Although the number of initial opioid prescriptions declined, a subgroup of providers continued to write high-risk initial opioid prescriptions. (Funded by the National Institute on Aging and a gift from Owen and Linda Robinson.).

How Emerging Telehealth Models Challenge Policymaking.

Policy Points Current telehealth policy discussions are focused on synchronous video and audio telehealth visits delivered by traditional providers and have neglected the growing number of alternative telehealth offerings. These alternative telehealth offerings range from simply supporting traditional brick-and-mortar providers to telehealth-only companies that directly compete with them. We describe policy challenges across this range of alternative telehealth offerings in terms of using the appropriate payment model, determining the payment amount, and ensuring the quality of care.

Medicare Spending after 3 Years of the Medicare Shared Savings Program.

BACKGROUND: Health care providers who participate as an accountable care organization (ACO) in the voluntary Medicare Shared Savings Program (MSSP) have incentives to lower spending for Medicare patients while achieving high performance on a set of quality measures. Little is known about the extent to which early savings achieved by ACOs in the program have grown and been replicated by ACOs that entered the program in later years. ACOs that are physician groups have stronger incentives to lower spending than hospital-integrated ACOs. METHODS: Using fee-for-service Medicare claims from 2009 through 2015, we performed difference-in-differences analyses to compare changes in Medicare spending for patients in ACOs before and after entry into the MSSP with concurrent changes in spending for local patients served by providers not participating in the MSSP (control group). We estimated differential changes (i.e., the between-group difference in the change from the pre-entry period) separately for hospital-integrated ACOs and physician-group ACOs that entered the MSSP in 2012, 2013, or 2014. RESULTS: MSSP participation was associated with differential spending reductions in physician-group ACOs. These reductions grew with longer participation in the program and were significantly greater than the reductions in hospital-integrated ACOs. By 2015, the mean differential change in per-patient Medicare spending was -$474 (-4.9% of the pre-entry mean, P<0.001) for physician-group ACOs that entered in 2012, -$342 (-3.5% of the pre-entry mean, P<0.001) for those that entered in 2013, and -$156 (-1.6% of the pre-entry mean, P=0.009) for those that entered in 2014. The corresponding differential changes for hospital-integrated ACOs were -$169 (P=0.005), -$18 (P=0.78), and $88 (P=0.14), which were significantly lower than for physician-group ACOs (P<0.001). Spending reductions in physician-group ACOs constituted a net savings to Medicare of $256.4 million in 2015, whereas spending reductions in hospital-integrated ACOs were offset by bonus payments. CONCLUSIONS: After 3 years of the MSSP, participation in shared-savings contracts by physician groups was associated with savings for Medicare that grew over the study period, whereas hospital-integrated ACOs did not produce savings (on average) during the same period. (Funded by the National Institute on Aging.).

Impact of an Episode-Based Payment Initiative by Commercial Payers in Arkansas on Procedure Volume: an Observational Study.

BACKGROUND: Episode-based payment (EBP) is gaining traction among payers as an alternative to fee-for-service reimbursement. However, there is concern that EBP could influence the number of episodes. OBJECTIVE: To examine how procedure volume changed after the introduction of EBP in 2013 and 2014 under the Arkansas Health Care Payment Improvement Initiative. DESIGN: Using 2011-2016 commercial claims data, we estimate a difference-in-differences model to assess the impact of EBP on the probability of a beneficiary having an episode for four procedures that were reimbursed under EBP in Arkansas: total joint replacement, cholecystectomy, colonoscopy, and tonsillectomy. PARTICIPANTS: Commercially insured beneficiaries in Arkansas serve as our treatment group, while commercially insured beneficiaries in neighboring states serve as our comparison group. INTERVENTIONS: Statewide implementation of EBP for various clinical conditions by two of Arkansas' largest commercial insurers. MAIN MEASURES: For a given procedure type, the primary outcomes are the annual rate of procedures (number of procedures per 1000 beneficiaries) and the probability of a beneficiary undergoing that procedure in a given quarter. KEY RESULTS: The relationship between EBP and procedure volume varies across procedures. After EBP was implemented, the probability of undergoing colonoscopy increased by 17.2% (point estimate, 2.63; 95% CI, 1.18 to 4.08; p < 0.001; Arkansas pre-period mean, 15.29). The probability of undergoing total joint replacement increased by 9.9% (point estimate, 0.091; 95% CI, - 0.011 to 0.19; p = 0.08; Arkansas pre-period mean, 0.91), though this effect is not significant. There is no discernable impact on cholecystectomy or tonsillectomy volume. CONCLUSIONS: We do not find clear evidence of deleterious volume expansion. However, because the impact of EBP on procedure volume may vary by procedure, payers planning to implement EBP models should be aware of this possibility.

Savings or Selection? Initial Spending Reductions in the Medicare Shared Savings Program and Considerations for Reform.

Policy Points Concerns have been raised about risk selection in the Medicare Shared Savings Program (MSSP). Specifically, turnover in accountable care organization (ACO) physicians and patient panels has led to concerns that ACOs may be earning shared-savings bonuses by selecting lower-risk patients or providers with lower-risk panels. We find no evidence that changes in ACO patient populations explain savings estimates from previous evaluations through 2015. We also find no evidence that ACOs systematically manipulated provider composition or billing to earn bonuses. The modest savings and lack of risk selection in the original MSSP design suggest opportunities to build on early progress. Recent program changes provide ACOs with more opportunity to select providers with lower-risk patients. Understanding the effect of these changes will be important for guiding future payment policy. CONTEXT: The Medicare Shared Savings Program (MSSP) establishes incentives for participating accountable care organizations (ACOs) to lower spending for their attributed fee-for-service Medicare patients. Turnover in ACO physicians and patient panels has raised concerns that ACOs may be earning shared-savings bonuses by selecting lower-risk patients or providers with lower-risk panels. METHODS: We conducted three sets of analyses of Medicare claims data. First, we estimated overall MSSP savings through 2015 using a difference-in-differences approach and methods that eliminated selection bias from ACO program exit or changes in the practices or physicians included in ACO contracts. We then checked for residual risk selection at the patient level. Second, we reestimated savings with methods that address undetected risk selection but could introduce bias from other sources. These included patient fixed effects, baseline or prospective assignment, and area-level MSSP exposure to hold patient populations constant. Third, we tested for changes in provider composition or provider billing that may have contributed to bonuses, even if they were eliminated as sources of bias in the evaluation analyses. FINDINGS: MSSP participation was associated with modest and increasing annual gross savings in the 2012-2013 entry cohorts of ACOs that reached $139 to $302 per patient by 2015. Savings in the 2014 entry cohort were small and not statistically significant. Robustness checks revealed no evidence of residual risk selection. Alternative methods to address risk selection produced results that were substantively consistent with our primary analysis but varied somewhat and were more sensitive to adjustment for patient characteristics, suggesting the introduction of bias from within-patient changes in time-varying characteristics. We found no evidence of ACO manipulation of provider composition or billing to inflate savings. Finally, larger savings for physician group ACOs were robust to consideration of differential changes in organizational structure among non-ACO providers (eg, from consolidation). CONCLUSIONS: Participation in the original MSSP program was associated with modest savings and not with favorable risk selection. These findings suggest an opportunity to build on early progress. Understanding the effect of new opportunities and incentives for risk selection in the revamped MSSP will be important for guiding future program reforms.

Early Performance of Accountable Care Organizations in Medicare.

BACKGROUND: In the Medicare Shared Savings Program (MSSP), accountable care organizations (ACOs) have financial incentives to lower spending and improve quality. We used quasi-experimental methods to assess the early performance of MSSP ACOs. METHODS: Using Medicare claims from 2009 through 2013 and a difference-in-differences design, we compared changes in spending and in performance on quality measures from before the start of ACO contracts to after the start of the contracts between beneficiaries served by the 220 ACOs entering the MSSP in mid-2012 (2012 ACO cohort) or January 2013 (2013 ACO cohort) and those served by non-ACO providers (control group), with adjustment for geographic area and beneficiary characteristics. We analyzed the 2012 and 2013 ACO cohorts separately because entry time could reflect the capacity of an ACO to achieve savings. We compared ACO savings according to organizational structure, baseline spending, and concurrent ACO contracting with commercial insurers. RESULTS: Adjusted Medicare spending and spending trends were similar in the ACO cohorts and the control group during the precontract period. In 2013, the differential change (i.e., the between-group difference in the change from the precontract period) in total adjusted annual spending was -$144 per beneficiary in the 2012 ACO cohort as compared with the control group (P=0.02), consistent with a 1.4% savings, but only -$3 per beneficiary in the 2013 ACO cohort as compared with the control group (P=0.96). Estimated savings were consistently greater in independent primary care groups than in hospital-integrated groups among 2012 and 2013 MSSP entrants (P=0.005 for interaction). MSSP contracts were associated with improved performance on some quality measures and unchanged performance on others. CONCLUSIONS: The first full year of MSSP contracts was associated with early reductions in Medicare spending among 2012 entrants but not among 2013 entrants. Savings were greater in independent primary care groups than in hospital-integrated groups.

Performance differences in year 1 of pioneer accountable care organizations.

BACKGROUND: In 2012, a total of 32 organizations entered the Pioneer accountable care organization (ACO) program, in which providers can share savings with Medicare if spending falls below a financial benchmark. Performance differences associated with characteristics of Pioneer ACOs have not been well described. METHODS: In a difference-in-differences analysis of Medicare fee-for-service claims, we compared Medicare spending for beneficiaries attributed to Pioneer ACOs (ACO group) with other beneficiaries (control group) before (2009 through 2011) and after (2012) the start of Pioneer ACO contracts, with adjustment for geographic area and beneficiaries' sociodemographic and clinical characteristics. We estimated differential changes in spending for several subgroups of ACOs: those with and those without clear financial integration between hospitals and physician groups, those with higher and those with lower baseline spending, and the 13 ACOs that withdrew from the Pioneer program after 2012 and the 19 that did not. RESULTS: Adjusted Medicare spending and spending trends were similar in the ACO group and the control group during the precontract period. In 2012, the total adjusted per-beneficiary spending differentially changed in the ACO group as compared with the control group (-$29.2 per quarter, P=0.007), consistent with a 1.2% savings. Savings were significantly greater for ACOs with baseline spending above the local average, as compared with those with baseline spending below the local average (P=0.05 for interaction), and for those serving high-spending areas, as compared with those serving low-spending areas (P=0.04). Savings were similar in ACOs with financial integration between hospitals and physician groups and those without, as well as in ACOs that withdrew from the program and those that did not. CONCLUSIONS: Year 1 of the Pioneer ACO program was associated with modest reductions in Medicare spending. Savings were greater for ACOs with higher baseline spending than for those with lower baseline spending and were unrelated to withdrawal from the program. (Funded by the National Institute on Aging and others.).

Diffusion of Bevacizumab Across Oncology Practices: An Observational Study.

BACKGROUND: Technological advances can improve care and outcomes but are a primary driver of health care spending growth. Understanding diffusion and use of new oncology therapies is important, given substantial increases in prices and spending on such treatments. OBJECTIVES: Examine diffusion of bevacizumab, a novel (in 2004) and high-priced biologic cancer therapy, among US oncology practices during 2005-2012 and assess variation in use across practices. RESEARCH DESIGN: Population-based observational study. SETTING: A total of 2329 US practices providing cancer chemotherapy. PARTICIPANTS: Random 20% sample of 236,304 Medicare fee-for-service beneficiaries aged above 65 years in 2004-2012 undergoing infused chemotherapy for cancer. MEASURES: Diffusion of bevacizumab (cumulative time to first use and 10% use) in practices, variation in use across practices overall and by higher versus lower-value use. We used hierarchical models with practice random effects to estimate the between-practice variation in the probability of receiving bevacizumab and to identify factors associated with use. RESULTS: We observed relatively rapid diffusion of bevacizumab, particularly in independent practices and larger versus smaller practices. We observed substantial variation in use; the adjusted odds ratio (95% confidence interval) of bevacizumab use was 2.90 higher (2.73-3.08) for practices 1 SD above versus one standard deviation below the mean. Variation was less for higher-value [odds ratio=2.72 (2.56-2.89)] than lower-value uses [odds ratio=3.61 (3.21-4.06)]. CONCLUSIONS: Use of bevacizumab varied widely across oncology practices, particularly for lower-value indications. These findings suggest that interventions targeted to practices have potential for decreasing low-value use of high-cost cancer therapies.

Prices for Common Services at Quaternary vs Nonquaternary Hospitals.

This study uses commercial claims data to assess whether quaternary hospitals charge higher prices for common, unspecialized services also offered by nonquaternary hospitals.

Changes in patients' experiences in Medicare Accountable Care Organizations.

BACKGROUND: Incentives for accountable care organizations (ACOs) to limit health care use and improve quality may enhance or hurt patients' experiences with care. METHODS: Using Consumer Assessment of Healthcare Providers and Systems (CAHPS) survey data covering 3 years before and 1 year after the start of Medicare ACO contracts in 2012 as well as linked Medicare claims, we compared patients' experiences in a group of 32,334 fee-for-service beneficiaries attributed to ACOs (ACO group) with those in a group of 251,593 beneficiaries attributed to other providers (control group), before and after the start of ACO contracts. We used linear regression and a difference-in-differences analysis to estimate changes in patients' experiences in the ACO group that differed from concurrent changes in the control group, with adjustment for the sociodemographic and clinical characteristics of the patients. RESULTS: After ACO contracts began, patients' reports of timely access to care and their primary physicians' being informed about specialty care differentially improved in the ACO group, as compared with the control group (P=0.01 and P=0.006, respectively), whereas patients' ratings of physicians, interactions with physicians, and overall care did not differentially change. Among patients with multiple chronic conditions and high predicted Medicare spending, overall ratings of care differentially improved in the ACO group as compared with the control group (P=0.02). Differential improvements in timely access to care and overall ratings were equivalent to moving from average performance among ACOs to the 86th to 98th percentile (timely access to care) and to the 82nd to 96th percentile (overall ratings) and were robust to adjustment for group differences in trends during the preintervention period. CONCLUSIONS: In the first year, ACO contracts were associated with meaningful improvements in some measures of patients' experience and with unchanged performance in others. (Funded by the National Institute on Aging and others.).

Changes in health care spending and quality 4 years into global payment.

BACKGROUND: Spending and quality under global budgets remain unknown beyond 2 years. We evaluated spending and quality measures during the first 4 years of the Blue Cross Blue Shield of Massachusetts Alternative Quality Contract (AQC). METHODS: We compared spending and quality among enrollees whose physician organizations entered the AQC from 2009 through 2012 with those among persons in control states. We studied spending changes according to year, category of service, site of care, experience managing risk contracts, and price versus utilization. We evaluated process and outcome quality. RESULTS: In the 2009 AQC cohort, medical spending on claims grew an average of $62.21 per enrollee per quarter less than it did in the control cohort over the 4-year period (P<0.001). This amount is equivalent to a 6.8% savings when calculated as a proportion of the average post-AQC spending level in the 2009 AQC cohort. Analogously, the 2010, 2011, and 2012 cohorts had average savings of 8.8% (P<0.001), 9.1% (P<0.001), and 5.8% (P=0.04), respectively, by the end of 2012. Claims savings were concentrated in the outpatient-facility setting and in procedures, imaging, and tests, explained by both reduced prices and reduced utilization. Claims savings were exceeded by incentive payments to providers during the period from 2009 through 2011 but exceeded incentive payments in 2012, generating net savings. Improvements in quality among AQC cohorts generally exceeded those seen elsewhere in New England and nationally. CONCLUSIONS: As compared with similar populations in other states, Massachusetts AQC enrollees had lower spending growth and generally greater quality improvements after 4 years. Although other factors in Massachusetts may have contributed, particularly in the later part of the study period, global budget contracts with quality incentives may encourage changes in practice patterns that help reduce spending and improve quality. (Funded by the Commonwealth Fund and others.).

Insurance Transitions and Changes in Physician and Emergency Department Utilization: An Observational Study.

BACKGROUND: Shopping for health insurance is encouraged as a way to find the most affordable coverage that best meets an enrollee's needs. However, the extent to which individuals switch insurance and subsequent changes in health care utilization that might arise, particularly new physician visits, are not well understood. OBJECTIVE: To examine the relationship between insurance switching and new physician and emergency department visits around the time of a switch. DESIGN: Observational study using a difference-in-differences design to compare those switching insurance carriers with propensity score-matched controls who did not switch, stratified based on whether individuals initially had private or Medicaid insurance coverage. All analyses adjusted for individual and insurance characteristics. PARTICIPANTS: Continuously insured, non-elderly individuals with private or Medicaid insurance coverage in Massachusetts from 2010 to 2013. MAIN MEASURES: Rates of new primary care and specialist physician visits, as well as rates of emergency department visits. KEY RESULTS: Before matching, among 1,628,057 continuously insured individuals, 418,231 (26%) switched insurance carriers during a 2-year period. Characteristics of switchers and non-switchers were similar after matching (n = 316,343 in each group). After matching, switching plans was associated with a 203% and 47.5% increase in the rate of new primary care physician visits following switching for those initially with Medicaid or private coverage, respectively (both p < 0.001), with a large short-term increase, diminishing over time. Among those with Medicaid coverage, switching was associated with a 14.9% higher rate of ED visits during the month of switching (p < 0.001), but otherwise decreased modestly after switching. CONCLUSIONS: Insurance switching is common, and is associated with increased new physician visits and temporarily increased ED use among the publicly insured. As insurance markets become more volatile in the current policy environment, understanding changes in utilization after insurance switching may become increasingly important.