Premium tiers set rates for coverage levels such as employee-only, employee plus spouse, employee plus children, and family. Tier structure and plan design together drive what employees pay and which options they pick.
Because employee needs vary, many employers offer a menu, a low/medium/high or “base-and-buy-up” structure, that lets employees self-select between richer, more predictable coverage and leaner, lower-premium plans. A single plan is simpler to administer but fits fewer people well.
Lower premiums usually buy higher cost-sharing (bigger deductibles and out-of-pocket costs), a narrower provider network, or both. The cheapest plan on premium isn’t automatically the cheapest for you: it depends on how much care you expect to use.