WASHINGTON — The Pentagon hopes to reap billions of dollars to pay for ships, aircraft and other weapons by doubling or tripling health insurance premiums paid by military retirees and driving 600,000 of those pensioners out of the military medical system, a coalition of veterans organizations charges.

Groups representing more than 1 million military pensioners — those who served at least 20 years — are organizing a telephone and letter-writing campaign to block the idea if it surfaces in Congress or to persuade the Bush administration to abandon it.

The retirees say the proposal breaks faith with former service members and their families, and risks alienating active duty troops who may see it as eroding their retirement benefits.

Because promises of free or low-cost healthcare are part of the military's recruiting effort, new fees could be an obstacle to recruiting, the veterans argue.

"They sort of pit us against the active duty force," said Michael Barrett, a retired Navy officer living in Williamsburg, Va.

A Defense Department spokeswoman did not confirm that fee increases are in the offing.

Yet Steve Strobridge, government relations director of the Military Officers Association of America, one of the more active lobbies for retirees, said the group learned of the plan from several independent sources.

The officers association, with 370,000 members, is one of several retiree groups circulating the list of proposed increases, which asserts that by 2009, the Pentagon wants to more than triple the annual premiums paid by retired officers younger than 65 for coverage under Tricare Prime, the military's premier health-insurance program.

That would raise those costs to $750 per year for individuals from today's $230, and to $1,500 from $460 per year for families.

Tricare Prime premiums for retired enlisted members younger than 65 would roughly double during the same period, the retiree groups say, as would the deductibles charged both officer and enlisted retirees in Tricare Standard, a less generous program.

Veterans groups say increased co-pays for prescription drugs for both active duty and retired troops also have been proposed.

Defense Department officials have complained for years that skyrocketing healthcare costs, particularly for retirees, are cutting into money needed to equip today's troops. The Pentagon's medical expenses have doubled in the past five years and could reach $64 billion annually by 2015, according to Pentagon estimates.

The retiree groups say the hikes are meant to trim $32 billion from the Pentagon's health costs by 2015. Most of the projected savings would come from the movement of an estimated 600,000 retirees from Tricare to health insurance plans obtained through civilian employers.