Medicaid work requirements for some beneficiaries will begin across the U.S. in January under President Donald Trump’s 2025 tax cut and policy law. Most covered adults must work or volunteer at least 80 hours a month or attend school at least half-time, although medical frailty and other circumstances qualify for exemptions. Federal rules allow states to accept a beneficiary’s self-attestation during the first year, but Arkansas, Idaho, Indiana, New Hampshire, North Carolina and Ohio will require documentation immediately, and other states are considering similar policies. The mandate covers up to 20 million lower-income adults under 65 without children at home in the 40 states and the District of Columbia that expanded Medicaid; most nondisabled beneficiaries in that group already work. The Congressional Budget Office estimates the changes will save $887 billion over a decade while leaving 7.5 million fewer people insured. Democrats in 25 states are suing, while conservative groups support stricter verification. Patient advocates warn that provider certifications, diagnosis codes and other paperwork could cause eligible applicants and people with mental health or substance use disorders to lose coverage. States must also upgrade eligibility systems and conduct most eligibility reviews twice a year.