If two or more companies are under common ownership and the total employee count is 50 or more FTEs, do the companies have to sign up under the same health plan?

No. While the companies are part of an aggregated applicable large employer group and therefore subject to the employer mandate and employer reporting requirements, if the companies have their own tax ID numbers, the separate companies can purchase their own health plans.

If the companies purchase separate health plans, they will do so in the small group or large group markets based on the average total number of employees (ATNE) in each separate company, not the total combined number of employees.