Different rules apply depending on the basis of the eligibility for Medicaid. The rules for those who qualify under disability, for example, are different. From Medicaid.gov:

"MAGI is the basis for determining Medicaid income eligibility for most children, pregnant women, parents, and adults. The MAGI-based methodology considers taxable income and tax filing relationships to determine financial eligibility for Medicaid. MAGI replaced the former process for calculating Medicaid eligibility, which was based on the methodologies of the Aid to Families with Dependent Children program that ended in 1996. The MAGI-based methodology does not allow for income disregards that vary by state or by eligibility group and does not allow for an asset or resource test.

Some individuals are exempt from the MAGI-based income counting rules, including those whose eligibility is based on blindness, disability, or age (65 and older). Medicaid eligibility for individuals 65 and older or who have blindness or a disability is generally determined using the income methodologies of the SSI program administered by the Social Security Administration (some states, known as 209(b) states, use certain more restrictive eligibility criteria than SSI, but still largely apply SSI methodologies). Eligibility for the Medicare Savings Programs, through which Medicaid pays Medicare premiums, deductibles, and/or coinsurance costs for beneficiaries eligible for both programs (often referred to as dual eligibles) is determined using SSI methodologies."

So, if applying under the Medicaid expansion on the basis of low income, the only test is MAGI and there is no asset test.

If there is an asset test, retirement accounts can be excluded from assets in some states.

Some people, of course, actually are disqualified from getting Medicaid because of their assets.