MEWA (Multiple Employer Welfare Arrangement)
A MEWA is a health or welfare benefit arrangement covering employees of two or more unrelated employers, the ERISA category most PEO health programs fall into.
The US Department of Labor treats an arrangement offering health benefits to the workers of multiple client employers as a multiple employer welfare arrangement. That classification matters because MEWAs are subject to both federal ERISA rules and a layer of state insurance regulation that varies by state, and some states restrict or heavily regulate self-funded MEWAs.
For a buyer, the MEWA lens replaces the vague phrase "large group plan" with checkable facts: whether the arrangement is fully insured or self-funded, which carrier or trust holds the risk, which states it is filed in, and what happens if the arrangement fails or exits your state. Ask for the plan documents and the funding structure in writing before treating a PEO health offer as equivalent to a carrier policy.