Health premium refunds due nearly 200,000 U.S. workers and retirees here could be delayed or lowered because of a lawsuit filed by former Blue Cross-Blue Shield policyholders who are seeking a share of the multimillion-dollar rebates being offered current subscribers and the government.

In May the giant health insurance company proposed to refund nearly half a billion dollars to the government, and almost $300 million to 1.4 million current policyholders. It said the unprecedented rebates were warranted because of a drop in health plan use that started last year.

The tax-free refunds to individual employes that range from $18 to more than $400 were approved by the White House. Congress is expected to approve special legislation to give similar refunds to retirees who currently hold Blue Cross-Blue Shield health insurance.

The first refund payments were expected to be mailed sometime in October.

But many former Blue Cross-Blue Shield subscribers who dropped the health plan this year for less costly coverage with other plans have objected to the insurance company plan to limit refunds to this year's policyholders.

On Tuesday, some of those former policyholders -- who had Blue Cross-Blue Shield insurance either last year or in 1983 -- filed suit in U.S. District Court. They are seeking an injunction that would bar any refunds from being sent to current workers or retirees until the question of refunds for former policyholders is decided.

Blue Cross-Blue Shield officials say the decision to limit refunds to 1985 policyholders was made because most of the savings came this year. Also, it is difficult, they said, to track down workers and retirees who switched out of the plan to other health plans this year or in 1984. The company says 30,000 policyholders switched out of its high option plan this year, and 35,000 left the standard option plan.

The refunds proposed before the lawsuit was filed amount to more than $400 for nonpostal workers and retirees with high option family plans and $190 for single policyholders. Refunds for postal workers would be $326 and $150 respectively. Nonpostal workers and retirees with standard family plans would get $179, and $73 for single plans. Postal worker rebates would be $51 and $18 respectively.

But if the court puts a hold on the refunds or decides to spread them among a larger group, the checks could be much later, and much smaller, than refund recipients had expected.

Other federal health insurance plans had until the middle of last month to request permission from the Office of Personnel Management to make refunds or some kind of premium adjustments.

OPM officials would not say yesterday if any of the other plans in the federal health program had responded. But a congressional source said that two or three other health plans may be making some kind of premium adjustments next year, possibly by lowering the amount they will charge in 1986.