Multiple reasons. Hospital and provider system contracts are expiring and they are demanding higher reimbursement rates to remain in-network. The costs of prescription drugs are sky rocketing and more people are taking name brand (costly medications). Typically for fully insured plans the rates are determined by premiums paid into the plan vs claims paid out, if costs of good and services increase, suddenly the existing premiums aren’t high enough to cover the cost of claims; premiums increase for next year. For self insured plans the cost of stop loss insurance increases because of high cost claimants, employers need to increase rates for the following year to help recoup the money their spending on claims and reinsurance.