An independent study from Consumers Union is revealing that a number of health insurers are stockpiling billions of dollars but continue to raise premiums by double digits each year.

The study primarily investigated popular Blue Cross Blue Shield non-profit insurers, who cover roughly one in three Americans with a private insurance plan. While the law varies from state to state as to how much money an insurer must set aside to maintain minimal solvency, seven out of ten of the insurers carried three times the minimal amount. Blue Cross Blue Shield of Arizona is holding seven times the minimal solvency amount, but raised its rates 14% to 19% for policy holders in 2007 and 13% to 15% in 2008. While Blue Cross Blue Shield of Arizona was one of the more egregious offenders, other insurers carried similar amounts of cash reserves and rate increases.

While insurers were quick to defend their reserves as necessary, Consumers Union believes that the law should require a maximum minimal insolvency amount in addition to the minimum. Considering the strength of the insurers’ current financial situations, Consumers Union suggested a refund to consumers, a fund to stabilize future rate increases, or charitable health care endeavors.