IOWA CITY, Iowa (AP) — Months after customers blasted the company for years of skyrocketing rates, Iowa's dominant health insurer said Tuesday it will limit premium increases in 2014 to less than six percent for individual and small business policyholders.

Wellmark Blue Cross and Blue Shield said in a statement it would not raise premiums to cover any increases in general medical or administrative costs in 2014. Instead, the Des Moines-based mutual company said it would only raise rates to offset the new fees required of insurance carriers under the Affordable Care Act.

The decision will impact 330,000 members in Iowa and South Dakota who purchase health insurance directly from Wellmark, or who get their insurance through small businesses with less than 50 employees. Wellmark, which insures roughly 1.8 million customers in Iowa and 300,000 in South Dakota, did not specify how larger group policies would be affected.