Over the past decade, the landscape of Medicare prescription drug benefits has undergone a dramatic transformation, reshaping the accessibility and viability of retail pharmacies across the United States. Recent research published in Health Affairs by scholars at the University of Southern California (USC) sheds light on how the proliferation of preferred pharmacy networks within Medicare Part D has not only altered the dynamics of pharmacy participation but also intensified the risk of closure among independent and community-centered pharmacies. This evolving paradigm significantly impacts the availability of pharmaceutical services, especially in underserved and socioeconomically vulnerable neighborhoods.
The concept of preferred pharmacy networks entails Medicare drug plans collaborating with a selective group of pharmacies, often incentivizing beneficiaries to fill prescriptions at these designated locations through lower copayments and better financial terms. Over the last decade, utilization of such networks surged remarkably, with the share of Medicare Advantage drug plans employing preferred networks tripling to 44%. Meanwhile, stand-alone Medicare prescription drug plans (PDPs) exhibited an increase from 70% to nearly universal inclusion of preferred pharmacies at 98%. This trend underscores a broader strategic shift within Medicare’s prescription drug framework, significantly influenced by the consolidation trends among pharmacy benefit managers (PBMs) and large retail pharmacy chains.
Pharmacy Benefit Managers, critical intermediaries in the prescription drug supply chain, wield considerable influence by designing these networks and determining which pharmacies qualify for preferred status. PBMs negotiate reimbursement rates and patient cost-sharing terms, effectively shaping patient choices by making some pharmacies financially more attractive. The vertical integration of PBMs with retail pharmacy chains further complicates this ecosystem, presenting potent conflicts of interest where PBMs potentially favor their owned or affiliated pharmacy outlets at the expense of independent competitors. This has prompted intense scrutiny by federal regulators and policymakers, as the arrangement raises concerns about anticompetitive practices that could ultimately reduce pharmacy access and choice.
The USC-led study provides robust statistical evidence that pharmacies excluded from these preferred networks face significantly higher risks of closure. Analyzing data spanning from 2014 to 2023, the researchers found that pharmacies outside of preferred networks were up to 4.5 times more likely to shut their doors than those included. This statistical disparity persists even after adjusting for differences in ownership structures and neighborhood demographic factors. Notably, pharmacies that were not preferred by any Part D plan had closure odds threefold greater than their network-inclusive counterparts, emphasizing the critical relationship between network inclusion and business sustainability in the Medicare market.
A revealing dimension of this research is its focus on the intersection between pharmacy closures and inequities in healthcare access. Independent pharmacies and those serving predominantly Black, Latino, or low-income neighborhoods were disproportionately excluded from preferred networks. In 2023, less than one percent of independent pharmacies were preferred by most Medicare Part D plans, whereas a substantial majority—around 70%—of chain pharmacies enjoyed preferred status. This disparity signals an exacerbation of existing healthcare disparities driven by network design choices, leaving marginalized communities increasingly vulnerable to pharmacy deserts, where pharmaceutical care options become severely limited or non-existent.
The geographic variability of preferred network participation adds another layer of complexity. In a cross-sectional analysis of thirteen diverse states, including New York and North Dakota, fewer than one-third of local pharmacies were favored by most Medicare plans. This regional heterogeneity suggests that beneficiaries’ access to preferred pharmacies is not uniform and heavily dependent on where they reside. The clustering of preferred network pharmacies in more affluent or predominantly white neighborhoods further marginalizes vulnerable populations, potentially exacerbating social determinants of health through restricted access to essential medication services.
Underlying this trend is the broader wave of mergers and acquisitions that have reshaped the pharmacy and PBM industries. Over recent years, the alliances between PBMs and major retail pharmacy chains have strengthened vertically integrated entities controlling large swaths of the prescription medication distribution pipeline. This confluence of interests incentivizes the preferential steering of patients toward in-house pharmacies, creating financial barriers for competing independent pharmacies and limiting patient choice. Regulatory bodies, including the Federal Trade Commission, have lamented these narrow networks in official reports that highlight the anti-competitive practices underlying preferred pharmacy creation.
The consequences of this market concentration are multifaceted. Beyond the immediate financial hardships on independent pharmacies, the restricted networks may lead to diminished access to personalized care, especially in communities that rely heavily on trusted local pharmacies as primary health access points. Moreover, pharmacy closures erode the infrastructure necessary to combat public health challenges such as medication adherence, chronic disease management, and vaccination outreach. The closure of pharmacies in marginalized neighborhoods thereby perpetuates a cycle where health disparities are compounded both by social and structural determinants.
Researchers emphasize the urgent need for federal intervention given the systemic nature of the problem. Potential policy remedies include imposing access standards that require Medicare Part D plans to maintain minimum levels of preferred pharmacy availability across all communities. Proposed regulatory changes might mandate broader, more inclusive networks or require the preferred status be granted more equitably, especially to critical access pharmacies that often operate in underserved regions. In parallel, increased reimbursement rates for pharmacies at risk of closure could bolster financial viability, helping to reverse the trend of closures in communities confronting pharmacy deserts.
This research offers key insights into shaping a more equitable pharmacy benefit design within Medicare. Addressing the conflicts of interest inherent in PBM ownership of pharmacies and designing networks that prioritize community health access over corporate profits are central to ensuring sustainable pharmacy care. Regulators might also explore transparency mandates requiring PBMs to disclose the criteria and processes behind preferred pharmacy selection, allowing for greater oversight and public accountability.
Emerging evidence shows that, while legislative efforts to reform PBM practices face significant challenges, administrative regulatory avenues could make meaningful impacts. For example, the Centers for Medicare & Medicaid Services (CMS) possesses tools to set standards for network adequacy and reimbursement policy within Medicare Part D. Proactive CMS guidance and enforcement could help dismantle exclusionary network practices and protect vulnerable pharmacies, preserving critical healthcare infrastructure in marginalized communities.
The USC study’s authors highlight that beyond the economic ramifications for pharmacies, the growing reliance on narrow preferred networks threatens to deepen health inequities already present in the U.S. healthcare system. Pharmacy access is a foundational element of primary healthcare, especially for elderly populations relying on Medicare. Thus, network policy decisions resonate beyond the counter or storefront—they reflect the accessibility of vital medication management and, by extension, the well-being of millions.
In summary, the expansion of preferred pharmacy networks within Medicare Part D embodies a seismic shift in the pharmaceutical services landscape shaped largely by PBM strategies and industry consolidation. This shift contributes to disproportionate pharmacy closures, particularly among independent operators in marginalized communities, potentially exacerbating healthcare disparities and limiting patient choice. The study advocates for urgent regulatory reform and policy action that enforces network adequacy, enhances reimbursement for at-risk pharmacies, and increases transparency in network formation. These steps are essential to preserving community pharmacy access, sustaining competition, and ultimately safeguarding equitable healthcare delivery to one of the nation’s most vulnerable demographics.
Subject of Research: Impact of Preferred Pharmacy Networks on Retail Pharmacy Closures and Health Equity in Medicare Part D
Article Title: Growth of Preferred Pharmacy Networks in Medicare Part D Linked to Increased Retail Pharmacy Closures and Disparities
News Publication Date: 5-May-2025
Web References:
- Health Affairs Research Article: https://www.healthaffairs.org/doi/full/10.1377/hlthaff.2024.01452
- FTC Interim Report on PBMs: https://www.ftc.gov/system/files/ftc_gov/pdf/pharmacy-benefit-managers-staff-report.pdf
- USC Study on Pharmacy Closures: https://schaeffer.usc.edu/research/pharmacy-closures-united-states-health-affairs/
- Pharmacy Deserts Information: https://schaeffer.usc.edu/pharmacy-deserts/
References:
Qato, D. M., Guadamuz, J., et al. (2025). Health Affairs. doi:10.1377/hlthaff.2024.01452
Image Credits: USC Schaeffer Center
Keywords:
Health care policy, Drug costs, Health care costs, Health care industry, Pharmaceuticals, Medical economics, Health care delivery
