More than 900 of President Reagan's favorite kind of civil servants--the waste- and fraud-chasing inspector general types at the Department of Health and Human Services--are set to lock their desks, pull the shades and turn out the lights next month because Uncle Sam can't give workers IOUs.

The IG people and thousands of other feds, at Labor, Education, Treasury, Commerce and some independent agencies, may be furloughed as early as July 5 unless Congress approves, and the president signs, an urgent supplemental appropriations bill.

The catch is that Congress has doubled the price tag on the legislation by adding billions of dollars for such non-salary items as mortgage subsidies and sewer grants. While many people consider those items vital to the economic recovery of the nation, they have little to do with IG offices, hearings before the Merit Systems Protection Board, agents who check for unregistered guns, untaxed liquor or cigarettes, or federal safety inspections.

President Reagan has warned he will veto the supplemental bill, even if it means shutting down parts of the government, if he considers it too expensive. White House sources say the package being worked out by Senate-House conferees is in danger of a veto.

Because of the potential salary cutoff, federal agencies have spent thousands of dollars alerting people to the possibility of a shutdown.

Productivity in some agencies, employes say, is zip these days as workers wonder if they will still be working after the Independence Day holiday.

For the folks at HHS this is the second furlough alarm in two months. In mid-May a "general notice of reduction-in-force (furlough)" went out to the 924 IG staffers here and in the field. Workers had to get individual copies, and sign a receipt that they had received and understood them. Those copies were sent out by Federal Express (for guaranteed next-day delivery) outside of Washington.

HHS was able to cancel that first furlough warning, by transferring funds from one account to its salaries and expenses fund. But last week, because the budget crisis continues, it had to go through the same expensive exercise again. Officials doubt they will be able to pull a rabbit out of a hat again, and say that unless the money is approved soon, furloughs will have to begin on or about July 5.

The same notification scene is being played in other departments that also face early-July furloughs because their supplemental payrolls are tied up in the legislation.

In addition to worrying about their finances, many employes are concerned about what a furlough will mean to their all-important health insurance coverage. This is what HHS is telling staffers who face furloughs on July 5:

"If you are enrolled in a federal health benefits plan, your enrollment will be terminated on July 10, 1982 [if the furloughs are still in progress .] Starting on July 11, 1982, you will have a 31-day grace period (July 11 through Aug. 10, 1982) during which your coverage will continue without cost to you. During this 31-day grace period you are entitled, and will have the opportunity, to convert to a private plan. The form you use for conversion will be provided you with the SF-50 (Notification of Personnel Action) effecting your furlough. Upon conversion to a private plan, you will be responsible for the full premium cost.

"If you elected to change your enrollment from one plan to another during the recent open season, the change will not be effected if we are required to go on furlough. You will continue to be covered under your old plan during the grace period.

"When you return from furlough, you will be treated like a new employe for health insurance purposes. That means you will have the opportunity to enroll in any plan of your choice. You will not have to wait for the next open season to do so."

This means that, in the unlikely event that the furloughs lasted more than 30 days, employes would lose their government health insurance coverage, and be forced to buy a private plan (at higher individual-rate premiums) if they wanted health protection.

Does anybody still wonder why morale in the federal workforce isn't what it used to be?