Is visitor insurance required for a B-2 visa?

What does the United States actually require of a B-2 visitor?

Nothing, in insurance terms. A consular officer weighs ties to your home country and your ability to fund the trip under INA 214(b), and neither the visa interview nor CBP inspection asks for a policy. The State Department still advises travelers to buy coverage, because Medicare does not cover visitors and an uninsured patient is billed directly.

Individual programs add their own conditions where federal law does not. Universities routinely require students to carry the school plan, and some exchange sponsors set limits above the federal floor. Those are contractual requirements from a sponsor or a school, enforceable against your standing in that program, not immigration rules applied at the border.

Source: U.S. Department of State, visitor visas

Which visa categories do have an insurance requirement?

Only J-1 exchange visitors carry a federal insurance minimum, set by 22 CFR 62.14 and enforced by the program sponsor for the visitor and any accompanying spouse or dependent. Failing to maintain it is a violation of program status. B-2, B-1 and F-1 holders have no equivalent federal rule.

Source: 22 CFR 62.14, insurance for exchange visitors

What happens if a visitor needs a hospital without coverage?

An emergency department at any hospital taking Medicare must screen you and stabilize an emergency condition regardless of insurance or immigration status, under EMTALA. That duty stops at stabilization, and it does not make the care free: the bill follows, and non-emergency treatment can be refused outright until payment is arranged.

Visitor medical plans exist for this gap. Fixed-benefit plans pay a scheduled amount per service; comprehensive plans pay a percentage after a deductible, up to a policy maximum. Neither is ACA coverage, both restrict pre-existing conditions, and the visitor hub sets out which structure suits which trip.