The two axes, and why the second one matters more to a saver. An income test asks what a household receives; an asset test, usually called a resource test, asks what it owns. Programs differ on whether they apply both. Supplemental Security Income and SNAP test income and resources. Premium tax credits on the health insurance marketplace test income only, with no asset test at all. Medicaid varies by eligibility category within one state, which is why a single answer about "Medicaid's asset limit" is usually wrong. For someone with modest income and any accumulated savings, the resource test is the one that decides the outcome, and it is the one financial decisions can accidentally trip.
The poverty guideline is the shared denominator. Rather than each program writing its own dollar figures, most express their limits as a percentage of the federal poverty guideline for the household's size: a program might use 100 percent, 130 percent, 138 percent or 400 percent of it. One consequence is administrative: a single annual table published by the Department of Health and Human Services moves eligibility for many unrelated programs at once. A second consequence is a trap for anyone doing arithmetic. Programs do not all use the same year's guideline, because each program's own rules fix which edition applies, and a program running on a fiscal year is generally working from the guideline in force when it set its limits rather than the current one.
The same two numbers, one indexed and one frozen. SNAP's resource limits start from a statutory $2,000, or $3,000 for a household including an elderly or disabled member, and 7 USC 2014(g)(1)(B) has adjusted them every October since 2008, rounded down to the nearest $250. Supplemental Security Income writes the same two figures, $2,000 for an individual and $3,000 for a couple, but its statutory schedule of increases ended in 1989 and contains no indexing mechanism, so those limits cannot move without an Act of Congress. Two programs chose identical numbers and only one of them still means what it meant when it was written.
Stacked phase-outs, and the effect they produce. Because a household can receive several means-tested benefits at once, and because each has its own phase-out, a raise can reduce more than one benefit simultaneously while also increasing tax and payroll withholding. The combined loss can approach or exceed the extra earnings, producing an effective marginal rate on that income higher than any statutory tax bracket. This is a real and well-documented feature of the system rather than a rhetorical point, and it is the reason advice to "just earn more" can be wrong in a specific, calculable way for a specific household.
Where this collides with financial planning, stated once. A resource test counts what a person owns, so money arriving outright can end eligibility for a benefit worth far more than the money. An inheritance left directly to a disabled beneficiary, a bank account retitled into their name, or a well-intentioned cash gift can each disqualify them. The established remedies are to route the value through a trust drafted for the purpose, or into an account type designed to be disregarded, rather than to hand it over. That mechanism belongs to the pages on those instruments; what belongs here is the reason it exists.
The statutory term of art, which is narrower than the phrase. "Federal means-tested public benefit" appears in 8 USC 1613, headed "Five-year limited eligibility of qualified aliens for Federal means-tested public benefit". It provides that a qualified alien entering the United States on or after August 22, 1996 "is not eligible for any Federal means-tested public benefit for a period of 5 years", with exceptions at subsection (b) for refugees, asylees, people whose deportation is being withheld, Cuban and Haitian entrants, Amerasian immigrants, and certain veterans and active-duty servicemembers and their spouses and children. Which programs are on the designated list is set by agency notice rather than by the statute, so the legal set is considerably smaller than the everyday description, and the two should not be used interchangeably.
What is not means-tested, because the contrast is load-bearing. Social Security retirement benefits and Social Security Disability Insurance are earned by paying payroll tax, so neither asks what you own. Unemployment insurance eligibility turns on work history and the reason for job loss, not on assets. Medicare eligibility is not means-tested either, and the qualification there is worth stating precisely: eligibility is not means-tested, but the Part B and Part D premiums a higher-income beneficiary pays are income-related, which is a surcharge on a benefit already earned rather than a test for getting it.