Medicare Advantage Faces Network Cuts as Costco Enters Market

A Turbulent Moment for Medicare Advantage

Medicare Advantage, the privately administered alternative to traditional Medicare, is having a complicated year. On one hand, enrollees are discovering that the hospitals and doctors they signed up for can disappear from their plan's network mid-year, with little warning and growing frequency 1. On the other, the market is expanding into unexpected retail territory, with Costco preparing to sell its own branded Medicare Advantage plans 34678. Together, these developments illustrate both the instability and the commercial momentum surrounding a program that now covers more than half of all Medicare beneficiaries.

Losing Coverage Without Losing the Plan

According to reporting on the hidden risks of Medicare Advantage, members can lose access to specific hospitals, hospital systems, or physician groups at any point during the plan year, not just during open enrollment 1. This is not a hypothetical concern: Naples Comprehensive Health announced it will stop accepting Cigna and Wellcare Medicare Advantage plans beginning in 2027, a decision that will directly affect patients who rely on that health system in southwest Florida 2. Disputes like this — often rooted in disagreements between insurers and providers over reimbursement rates — are becoming more common nationally, leaving beneficiaries to either switch plans, pay out-of-network costs, or find new doctors altogether 12.

New Research Questions on Outcomes

Adding to the scrutiny, a new study examined older adults with Type 2 diabetes and found that those enrolled in Medicare Advantage did not see better health outcomes compared with beneficiaries in traditional Medicare 5. The finding challenges one of the core marketing pitches of Advantage plans — that coordinated, privately managed care leads to superior results — and adds to a broader debate among policymakers and researchers about whether the program's growth has delivered on its promises.

Costco's Entry Signals Continued Market Growth

Despite these concerns, the Medicare Advantage market keeps attracting new entrants. Costco is partnering with nonprofit insurer SCAN Group to offer jointly branded Medicare Advantage plans, marking the warehouse retailer's first foray into health insurance 3478. The rollout will initially be limited to a small number of states, with a Medicare supplement product also planned for a third state, and the offering remains subject to federal approval 48. NPR's coverage framed the move as part of a wider trend of consumer brands moving into health insurance distribution, a strategy aimed at leveraging Costco's membership base and reputation for value 6. USA Today noted the cultural novelty of the pairing, tying the launch to Costco's famously cheap food-court offerings as a symbol of the retailer's low-cost brand identity 4.

What It Means for Beneficiaries

Taken together, the coverage suggests a market in flux: expanding in reach and retail partnerships, yet increasingly criticized for network instability and uncertain clinical benefits. For current and prospective enrollees, the lesson emerging from this reporting is that plan selection now requires more vigilance than ever — checking not just premiums and star ratings, but the durability of provider networks and the actual evidence behind promised health outcomes.