Employer Contribution

The employer contribution is the portion of the health plan premium (or, on a self-funded plan, the funding rate) that the employer pays on the employee's behalf. The rest is the employee contribution, deducted from pay before taxes.

Employers on average cover about 83 percent of the cost of single coverage and about 75 percent of family coverage, though the range is wide. Many employers pay a high share for the employee and a much smaller share for dependents, which is why adding a spouse and two kids can push a paycheck deduction from $150 a month to $900. The contribution strategy is also where a lot of plan design gets done quietly: a company that wants people on the high-deductible plan will often fund an HSA with $1,000 or more and price that plan's contribution well below the PPO. Under the ACA, the employee's share for single coverage on the cheapest qualifying plan must stay under about 9 percent of household income or the employer can face penalties.

The takeaway: look at the full contribution grid at open enrollment, not just the plan with the lowest employee deduction. An employer HSA deposit is real money and belongs in the comparison.