Short answer: Businesses under common ownership can be treated as a single employer under IRS rules. For the ACA, all employees of a commonly owned or affiliated group are combined to test the 50 full-time-equivalent threshold for Applicable Large Employer status. If the combined group is large, each related company is still treated as its own ALE member for penalties and reporting.
Common ownership, often called the controlled group rules, can combine separate but related businesses into a single employer for benefits and ACA purposes. The rules come from Internal Revenue Code section 414, and they keep an owner from sidestepping requirements simply by splitting a workforce across several companies.
How it affects ALE status:
To decide whether the employer mandate applies, you add together the full-time and full-time-equivalent employees of every company in the group. A set of small companies that each look under 50 employees on their own can be an Applicable Large Employer once combined. After the group is an ALE, each company, called an ALE member, still handles its own employer mandate exposure and its own Form 1095-C reporting.
Common types of related groups:
The rules generally cover three structures:
- Parent-subsidiary, where one company holds a controlling interest in others.
- Brother-sister, where the same small group of owners controls multiple companies.
- Affiliated service groups, where companies work together to deliver services.
These rules also affect other thresholds that depend on headcount, such as the 20-employee test for federal COBRA and benefit plan nondiscrimination testing. Ownership can be attributed among family members and related entities, so the analysis turns technical quickly and is worth confirming with a benefits advisor or accountant.