WASHINGTON — The typical Medicare beneficiary can expect to see about a $3 increase in their monthly premiums for prescription drug coverage in 2009, federal officials said Thursday.

Officials made the projection based on bids from private insurers that get the premiums along with a federal subsidy to administer the benefit. The increase of 12 percent will up the monthly premium to $28 for standard drug coverage.

Medicare officials cited several factors in the increase. Primarily, people are using more prescriptions, plus the costs of many of those drugs are going up.

Despite the increase, Medicare officials said the monthly premiums are still way below what was projected when the program was approved in 2003. Then, projections were for premiums next year to come in at around $44. Officials have said the program's lower costs are attributable to three main factors — lower enrollment, drug prices went up less than expected in the two years before the program began and insurers have been able to negotiate greater discounts than anticipated.

Overall, about 17.4 million people have enrolled in plans that just offer Medicare drug coverage. Another 7.6 million are enrolled in plans that provide comprehensive health coverage. About 10 million people get drug coverage for little or no cost because of additional government subsidies. For them, the average value of the drug benefit is estimated to be about $3,900 next year.