Say someone lives in county A, which is in the same state as county B. The Employer, based in the same state as both counties, offers different health insurance plans to someone living in county A than they offer to someone living in county B, even though both people are doing the same job (same job title, same responsibilities, same level) in the same geographic location. The costs of the health insurance appear to be the same (at least to the employee), but one could argue the plan offered to a person living in county A is better based on the flexibility available within the plan.
Can the employer deny eligibility to the person who lives in county B? If not, what statutes or legal arguments support this perspective?