This bill establishes the Medicare Exchange health plan (Medicare-X), a new public health insurance option designed to provide coordinated and low-cost access to quality healthcare. The Secretary of Health and Human Services is directed to make this plan available in the individual and small group markets across all rating areas by plan year 2028. To fund its creation and administration, the bill appropriates $1 billion each to a Plan Reserve Fund and a Data and Technology Fund for fiscal year 2027. Eligibility for Medicare-X is limited to qualified individuals under the Affordable Care Act who are not eligible for traditional Medicare, with enrollment facilitated through existing American Health Benefit Exchanges. The Medicare-X plan must adhere to all applicable Qualified Health Plan requirements under the ACA, offering at least silver and gold levels of coverage, and providing primary care services with no cost-sharing. Premiums will cover full actuarial and administrative costs, varying geographically, while provider reimbursement rates will generally mirror original Medicare fee-for-service rates, with potential increases for rural areas and negotiated prices for prescription drugs. Healthcare providers participating in Medicare or Medicaid will generally be required to also participate in Medicare-X by January 1, 2028, though an opt-out process exists for exceptional circumstances. The legislation promotes innovative payment mechanisms and delivery system reforms, including integrating medical care with social services and leveraging telehealth to improve health outcomes and reduce disparities. Beyond the public option, the bill significantly expands the Affordable Care Act's premium tax credits by removing the 400% poverty line income cap and adjusting subsidy levels for greater affordability. It also addresses the "family glitch" by basing affordability on family coverage costs for dependents, repeals the prohibition on Medicare negotiating prescription drug prices, and authorizes substantial funding to strengthen antitrust enforcement in healthcare markets.