Medicare Part D Pharmacy Networks in 2026: Supermarkets Dominate as Drugstores Stall and Independents Walk Away

The Centers for Medicare & Medicaid Services (CMS) has just released its initial 2026 data on enrollment in Medicare Part D prescription drug plans (PDPs).

DCI’s exclusive analysis shows that 83% of seniors remain enrolled in PDPs with preferred pharmacy networks—essentially unchanged from 82% in 2025, but sharply lower than the 99% peak in 2023. Meanwhile, the number of major Part D plans offering preferred networks has fallen to a record-low eight.

The new enrollment data reveal a clear shift in competitive positioning: Albertsons and Publix are now preferred in every major plan. Walgreens is holding strong. Walmart—the company that invented the Part D preferred network model—has slipped to the middle of the preferred pack.

Meanwhile, smaller pharmacies have fully abandoned PDPs’ preferred networks in 2026.

At the same time, the IRA’s expansion of the Low-Income Subsidy (LIS) means a growing share of beneficiaries have little financial incentive to use a preferred pharmacy at all. Add in the PBM reforms in the Consolidated Appropriations Act of 2026, and the preferred network model will gradually lose relevance.

PART D IN 2026

A preferred network gives consumers a choice of pharmacy while providing financial incentives to use the pharmacies that offer the payer lower costs or greater control. Within the Medicare Part D program, CMS calls these preferred cost sharing networks and refers to participating pharmacies as preferred cost sharing pharmacies.

In Medicare Part D 2026: Preferred Networks Vanish as the PDP Market Collapses, we explain how the Inflation Reduction Act of 2022 (IRA) has nearly obliterated the stand-alone Medicare Part D prescription drug plan (PDP) market:

• The number of PDPs has plummeted by 55% since the IRA’s passage, to a record low of 360 plans for 2026.

• Preferred cost-sharing pharmacy networks are disappearing, with their share falling to the lowest level since 2014—a post-IRA net loss of 505 plans with these networks.

• For 2026, just five major companies are offering 10 major multi-regional Part D plans—8 plans with a preferred network and two plans with an open network. These PDPs account for 91% of all regional PDPs and 96% of stand-alone PDP enrollment.

Large chains negotiate directly with PBMs and other third-party payers. By contrast, nearly all smaller pharmacy owners participate in pharmacy services administrative organizations (PSAOs) to leverage their influence in contract negotiations with PBMs and other third-party payers.

The largest PSAOs are owned by the three largest pharmaceutical wholesalers—Cencora, Cardinal Health, and McKesson. We profile the PSAO market here: Inside the 2025 PSAO Market: How Wholesalers Shape Pharmacy–PBM Relationships. McKesson's Health Mart and Cencora’s Good Neighbor Pharmacy score higher than their peers and large retail chains in customer satisfaction surveys.

The Part D open enrollment period ran from October 15, 2025, to December 7, 2025. You can download enrollment data here: Medicare Advantage/Part D Contract and Enrollment Data.

For a deep dive into the economics and strategies of narrow network models in both government and commercial plans, see Chapter 7 of our 2026 Economic Report on U.S. Pharmacies and Pharmacy Benefit Managers. (Don’t fret! The 2026 edition is coming soon!)

CHAIN REACTION

For 2026, the major pharmacy chains are maintaining their position in the remaining preferred networks. But the distribution of preferred lives tells a much more competitive story.

The table below summarizes the preferred status of six large retail chains in the plans offered by these five major insurers for 2026. No chains were added as a preferred pharmacy to a 2026 network (vs. 2025). Kroger was removed as a preferred pharmacy from the HCSC plans (vs. 2025).

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The chart below shows total enrollment (in millions) in preferred-network PDPs for which each chain is a preferred pharmacy. Plans with open networks are excluded from the enrollment computations.

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Here are the highlights of pharmacy participation in 2026 Part D preferred networks:

• CVS Health. After expanding preferred participation beginning in 2018, CVS pharmacies are preferred in only the two Wellcare plans with preferred networks in 2026. It is also in-network with the two open networks. Note that Aetna’s SilverScript Choice plan switched to an open network for 2025.
  
  For 2026, CVS pharmacies are preferred in plans that enrolled 8.8 million people (vs. 7.9 million in 2025), driven primarily by Wellcare growth.

• Walgreens. Since 2021, Walgreens has focused on participation in preferred networks. For 2026, it is preferred in six of the eight plans with preferred networks and participates in the two open networks.
  
  Based on the initial enrollment data, 12.7 million people are enrolled in the six plans in which Walgreens participates as a preferred pharmacy.

• Walmart. Beginning in 2020, Walmart reengaged with preferred cost-sharing networks. For 2026, it again is a preferred pharmacy in six of the eight major plans and participates in the two open networks. Note that Walmart and Humana launched the first Part D preferred network plan in 2010, although Humana has not offered this co-branded plan since 2023. The Humana Walmart Value Rx Plan was renamed as the Humana Value Rx Plan.
  
  Consequently, 6.1 million people are enrolled in plans with Walmart as a preferred pharmacy—essentially flat versus 6.2 million in 2025.

• Kroger. For 2026, Kroger is preferred in four of the eight major preferred networks and also participates in the two open networks. For 2025, Kroger had rejoined Express Scripts’ pharmacy networks, but is not preferred in the Cigna plans now owned by HCSC.
  
  Despite losing HCSC preferred status, Kroger’s preferred enrollment exposure rose to 11.2 million (vs. 10.5 million in 2025), reflecting Wellcare’s gains.

• Albertsons/Publix. Both Albertsons and Publix are participating in the eight preferred and two open major 2026 pharmacy networks, making them the most active retail pharmacy participants.
  
  Both chains top the list with 14.9 million preferred-network enrollees (vs. 14.0 million in 2025), the largest exposure of any retail pharmacy.

SMALL PHARMACIES RUN AWAY

To complement our analyses of retail chains, we evaluated PSAO participation in the same Part D plans. The top four PSAOs contract for more than 20,000 pharmacy locations. For 2026, these PSAOs have almost fully abandoned PDPs’ preferred networks:

• For 2026, McKesson’s Health Mart Atlas (HMA) is directly participating in only two of the HCSC plans. For the Humana Part D plans, its members can choose to participate as a preferred vs. a standard cost-sharing pharmacy for 2026. For the other national plans, HMA members are non-preferred.

• Cencora’s Elevate continues to believe that patients pick their pharmacy and then pick their Part D plan. For the ninth consecutive year, its members will not be preferred in any major plan for 2026.

• Cardinal’s LeaderNET PSAO continued the change in strategy that began in 2024. Like its peer PSAOs, Cardinal Health’s PSAOs have fully disengaged from preferred status in Part D networks for 2026.

• AlignRx. For 2026, none of AlignRx’s three PSAOs—AlignRx APN, RxSelect, and TriNet—will have preferred status in any major stand-alone Part D plan. For plans from Humana and Centene, there is no PSAO-level contract. For the other PDPs, its members’ pharmacies are non-preferred.

• For the sixth year, plans from Humana, WellCare, and UnitedHealthcare will not have any independent pharmacies participating via PSAOs as preferred pharmacies.

UNPREFERRED

Chains keep playing the preferred network game, while independents are exiting because the retail economics of preferred networks no longer make sense. Legislative changes have—and will—further diminish the role of preferred networks.

Beneficiaries who qualify for the Low-Income Subsidy (LIS) face low out-of-pocket drug costs regardless of a pharmacy’s preferred status. The Inflation Reduction Act (IRA) expanded eligibility to beneficiaries with incomes up to 150% of the federal poverty level (FPL). As LIS enrollment rises, the financial leverage of preferred networks diminishes.

Earlier this month, Section 6223 of the Consolidated Appropriations Act, 2026 (P.L. 119-75), which just became law, will dramatically alter how pharmacy networks operate within both stand-alone PDPs and Medicare Advantage prescription drug plans.

As these reforms take effect, the volume-steering economics that sustain preferred networks will weaken. Combined with an imploding PDP market, Part D’s preferred networks increasingly resemble a legacy contracting tool whose time may have passed.