Age Banded Health Insurance Rates

Why does everyone on our health plan have a different premium?

You pulled the rate sheet for your small group plan, expecting one number for single coverage and one for family. Instead there’s a different premium for almost every employee on the same plan. Nobody did anything wrong — that’s age-banded rating, one of the common ways small group premiums get built.

Small group generally means employers with up to 50 employees, though some states extend the definition to 100, so the exact cutoff depends on where you are and how employees are counted. For ACA-compliant, fully insured plans in that market, carriers can vary the premium for the same coverage on only four things: age, geography, family size, and tobacco use. Your group’s health history, claims, gender, and industry can’t be used as rating factors at all. Under age-banded rating, age is applied per person — the carrier assigns each enrolled member their own premium off an age curve — so the group premium is built from member-level rates rather than one flat employee or family rate. Federal rules generally limit age-based premium differences among adults age 21 and older to 3:1; states can impose tighter limits.

Two things tend to trip up HR here. First, these are carrier premiums, not what employees actually pay — an employee’s payroll deduction depends on how you’ve set up the employer contribution, which is a separate decision from how the carrier rates the plan. Second, the premiums aren’t recalculated on everyone’s birthday; age is generally set at issue or renewal, so an individual’s premium may change at renewal rather than stepping up automatically each year. And because you’re really paying the sum of a set of individual premiums, two groups with the same headcount can owe different totals when their ages or family enrollment differ.

What a family premium actually looks like

Because a family’s premium is just the sum of its members’ individual rates, it helps to see the arithmetic. The figures below are an illustration using the federal default age curve — not a real quote — starting from a hypothetical $400 base premium at age 21:

So a couple with two young kids is billed $1,621.60 — not a flat “family tier” number. A third child age 14 or younger would add another $306; a fourth would add nothing, because only the three oldest covered children under 21 count toward the family premium — additional younger children under 21 add no premium.

Two wrinkles worth knowing. Under the federal default curve, children aren’t all rated the same: rates are flat through age 14, then step up each year from 15 to 20. And a dependent aged 21 to 25 is rated as an adult, so that adult rate is added in full and isn’t subject to the three-child cap.

Age-banded rating isn’t the only structure. Some markets offer composite (flat) rating, where the carrier bills established average rates that stay fixed through the plan year — though the total bill can still move as people enroll or leave — and a few states community-rate without age variation at all. Composite billing can simplify the carrier side, but how your employees’ payroll deductions should be structured is a separate question either way. Fellow Travelers can walk you through how your current plan is rated and how your contribution setup interacts with it.