Average monthly premiums for individual health insurance in 2010 were highest in Vermont and Massachusetts, where residents paid an average of over $400 per member per month, according to a recently released study by the Kaiser Family Foundation. Rates were lowest in Alabama – $136 per member per month – followed by California, Arkansas, and Idaho.

The study was designed to compare average monthly premiums paid by individuals for health insurance coverage across the U.S. The data examined insurance rates for people who do not receive health insurance benefits through their employer or public programs.

The report, entitled Mapping Premium Variation in the Individual Market, found “substantial diversity in the insurance people buy across the country.” Potential reasons for the disparity in premiums include in cost of living, healthcare costs, state demographics (age distribution of population), plans’ effectiveness at controlling costs, benefits offered by the plans, and patient cost-sharing requirements, according to the report.

Per the Affordable Care Act, beginning in 2014,individuals without employer-sponsored insurance plans will be able to buy insurance directly through an Affordable Insurance Exchange, defined as “a new transparent and competitive insurance marketplace where individuals and small businesses can buy affordable and qualified health benefit plans,” according to the U.S. Department of Health & Human Services.