"The cause of the customer satisfaction decline is not difficult to find--sharp increases in premium costs and deductibles are to blame," said Claes Fornell, founder of the ACSI and author of "The Satisfied Customer: Winners and Losers in the Battle for Buyer Preference."

"Medical costs are rising and companies are passing on a greater share of the insurance burden to employees. When consumers pay more without getting better service, they are obviously not happy."

Life and property insurance are tied with credit unions for the highest ACSI score in financial services. The life insurance industry gained 1.3 percent to 80, while property & casualty insurance is unchanged at 80.

Smaller life insurers led the category, up 1 percent to 81. Northwestern Mutual topped the big companies, despite a small 1 percent dip to 80, followed by New York Life, down 3 percent to 78. MetLife and Prudential--the largest players in the life insurance business--are close behind, with MetLife up 1 percent to 78 and Prudential unchanged at 77.

Among property & casualty companies, State Farm maintained the lead, unchanged at 82, followed by GEICO, also unchanged at 81. Progressive and Allstate each fall 1 percent to 79 and 78, respectively, while Farmers dropped 3 percent to 76 to round out the industry.

2010 marks the fourth consecutive year that Farmers has occupied the bottom spot.

"Life and property & casualty typically do better with customers compared to health insurers because premiums are lower and policyholders have fewer reasons to interact with the insurance company, so there are fewer opportunities for things to go wrong," said Fornell. "This is particularly true for life insurance--premiums typically are fixed for the duration of the policy, and once a policy is in place, a customer might never again interact with the insurer."