Foundations of Medicaid

State and federal governments have responsibility for funding Medicaid. Because of this shared responsibility, Medicaid programs and services can be very different from state to state. This is unlike the federal Medicare program, which is administered in a fairly consistent manner in all U.S. states and territories.

Medicaid Programs Vary by State

State rules on Medicaid can vary across all components of the program, including:

  • Covered services
  • Reimbursement
  • Income eligibility requirements
  • Service delivery

In addition, many states have successfully petitioned the federal government to make changes to core components of their Medicaid programs, again making it difficult to describe aspects of Medicaid programs that are applicable across state lines.

To learn about your state’s Medicaid program requirements and who to contact for more information, visit

Tip: If you have a potential transplant patient at your center who is enrolled in Medicaid, learn about Medicaid coverage rules for transplant.

ACA Expands Medicaid in Some States

An important change brought about by the passage of the ACA (Affordable Care Act) in 2010 is a significant expansion in both eligibility for and federal funding of Medicaid. Under the law, all U.S. citizens and legal residents with income up to 133% of the poverty line, including adults without dependent children, would qualify for Medicaid coverage.

However, after the program was launched many states fought to make the program voluntary. As a result, it is a voluntary program and not all states are moving forward with expansion, and some states are finding different ways to cover low-income adults.  States which did not expand the Medicaid program to low-income adults, continue with pre-ACA funding levels and eligibility standards.

Because each state is different in terms of expansion and eligibility rules, it is important that you understand how to determine if a patient may be eligible for Medicaid. View the website and select a state to view: a Medicaid-Marketplace Overview, Medicaid and CHIP Eligibility Levels, and more.

For Dual Medicare and Medicaid Coverage, Medicare is the Primary Payer

There are more than 9 million dual Medicare-Medicaid enrollees, also known as dual-eligible individuals. The dual-eligible population mostly consists of low-income seniors and people with disabilities.      

Tip: Medicare is always the primary insurer for individuals who have dual coverage. 

For patients with dual coverage you must follow the rules for Medicare when it comes to transplant. Medicaid then covers Medicare premiums, co-pays, and any other services that are not covered by Medicare.

Further complicating matters is that some beneficiaries have only partial dual coverage which only covers cost-sharing (such as co-pays) and premiums – it does not extend Medicaid coverage for items and services not covered by Medicare.

In addition, some dual-eligible beneficiaries may receive coverage of prescribed medications through Medicare Part D prescription drug plans. These multiple-carrier delivery and financing options add an additional layer of complexity for individuals covered under both Medicare and Medicaid.

A new federal Medicare-Medicaid Coordination Office, established by the Patient Protection and Affordable Care Act (ACA), serves people who are enrolled in both Medicare and Medicaid.


    Visit the Medicare-Medicaid Coordination Office page for the most up-to-date information on all aspects of determining coverage of services for dual-eligible patients.
  • Medicare & Other Health Benefits: Your Guide to Who Pays First (PDF from
    Find more information on dual coverage that will be helpful to you and your patients.
    Learn about your state’s Medicaid program requirements and who to contact for more information.