The work force shuffle is already on.

As the armed forces start pulling in reservists to serve in the Middle East crisis, Washington-area businesses, hospitals and police and fire departments are scrambling to make their own contingency plans for plugging expected gaps of workers created by the call-up.

Employers also are grappling with the top concerns of many reservists: what to do about a sudden drop in pay when taking unpaid leave to go on active military duty and how to provide health benefits for their families. A few local businesses, such as MCI Communications Corp. and Inova Health Systems, already have decided to extend employee pay for several weeks after a worker goes on leave and to continue full health benefits for the duration of the employee's service.

In the District, Police Chief Isaac Fulwood Jr., who has ordered all commanders to count their reserve officers, said he is worried that a call to active military duty could deplete the department of badly needed senior members.

"We've got a war of our own, and this is a real shooting war," Fulwood said.

Although the Bush administration has authorized mobilization of up to 49,703 reservists and National Guard members by Oct. 1, the initial call-ups are coming gradually.

In the Washington region, more than 70,000 reservists and guard members are subject to be called, although many fewer are likely to be activated. Few area employers have noticed an impact on their operations yet, but many have decided they need to prepare both for critical losses and reassess military leave policies.

MCI, the Washington-based long-distance telephone company, developed a plan this week to deal with the pressure of increased business at a time it expects a number of its young, highly skilled work force to be called on short notice.

"We are feeling more and more pressure to provide services on an international basis because of the crisis," said John H. Zimmerman, senior vice president of human resources. "We've started working to make sure we don't have a soft underbelly in any area."

America's pursuit of international security in the Persian Gulf, meanwhile, is sending waves of worry through private security agencies at home.

According to interviews with local and national private security operations, military-connected employees make up one-third to three-quarters of the ranks of guards of these companies.

"We draw an awful lot of people from the military reserves," said Al Turner, personnel manager of Wells Fargo Guard Services in Bethesda. About 100 of the 300 guards working for Wells Fargo in the Washington area belong to the National Guard, military reserves, or are on active military duty, he said.

"We have some very, very sensitive positions that carry the highest levels of clearance. Those guard positions are easiest to fill with military people who already have high security clearances," said Macon Simms, operations officer at Guardian Security Agency Inc. in Wheaton.

Guardian employs 1,000 guards, mostly at Washington federal buildings. Of that number, about 300 are either on active or reserve military duty or belong to the National Guard, Simms said. The company already had made some adjustments in its scheduling after an entire shift of Guardian employees became unavailable last summer because they were all in a squadron at Quantico Marine base that was sent on special maneuvers.

Doctors and nurses are on a priority list to be called to active duty, and hospitals and other health-care facilities are busy assessing how many people they might lose.

"We have many doctors and nurses who have been in the military," said Sandra R. Gregg, a spokeswoman for Washington Hospital Center, and personnel managers now are counting how many hospital employees are in the reserves. "We have already lost two or three people" to active duty, Gregg said. "That you can handle, but if we get significantly more than that, it could be a real squeeze."

Nurses may present more of a problem than doctors if large numbers are called from the area, some health-care professionals said.

"Everyone already is working in a shortage situation as it is," said Evelyn Sommers, executive director of the D.C. Nurses' Association. While having no firm numbers, she said many nurses in the Washington area have been in the military.

Because there is no alternative pool of nurses to draw from, hospitals and other medical facilities will have to put those that remain on longer shifts and more shifts, the method used to overcome current shortages, Sommers added.

At Prince George's Hospital Center, the hospital is bracing for several doctors and nurses who are reservists to be transferred to other facilities such as Bethesda Naval Medical Center.

"Because of their background, we anticipate they will go," said Reggie Sanders, hospital spokesman.

Another specialty in demand by the armed forces is water purification experts, which could affect some public water and sanitation facilities.

"I'm sure it will" have an impact, said Jack C. Gilbert, human resources director for the Washington Suburban Sanitary Commission, because many of the water facilities' employees are in the reserves or National Guard. WSSC is trying to determine where its operations will be affected and next week plans to inform employees that their health benefits will stay in effect, with WSSC continuing to pay 90 percent of costs, for the duration of active duty, Gilbert said.

Businesses connected with the defense industry may find themselves doubly affected as they work on critical projects but lose key personnel to the reserves.

"Many of our key people have been participating in the reserves," said David Roth, senior vice president of Columbia-based General Physics Corp., which provides training and systems development to the Navy and private industry. "We are concerned about participation in some of the contracts."

At GRC International, which provides research and analysis to the Pentagon and makes electronic products, the impact overall is expected to be minimal because the company has counted only 42 reservists out of 1,350 employees.

But areas where both high technical skills and high-level security clearances are required could experience some difficulties even if only three or four key people are called, said Robert E. Wengler, chairman and chief executive officer.

In those areas, the company would temporarily promote others who have worked on the same project, Wengler said.

Local governments expect their law enforcement and public safety areas to be more affected than others once the calls start taking effect, though most say the call-up should not cause significant disruptions. Several have done head counts of reservists, however, just to be prepared. In Arlington, the greatest impact may be felt in at the jail because the sheriff's office has five to 10 of its 130 correctional officers in the reserves.

"Even if we were operating at full strength numerically, that would affect our operations," said Beth Arthur, director of administration for the sheriff's office. "We have a minimum standard of personnel based on the jail population, and we would probably be forced to having people work overtime if we lost that many people, which would cost us a lot more money."

Reservists typically must go on leave without pay but receive military pay while on active duty.

A master sergeant with six years of service makes base pay of $1,218 a month (or $14,619 a year) plus $361 a month in housing allowance for someone with dependents. A captain with eight years' service makes base pay at a rate of $31,564 a year, plus a $495 housing allowance for dependents, while a major would make about $35,000 a year, plus a $598 housing allowance.

Employers must protect an employee's job status while he or she is on reserve duty but does not have to extend benefits. The reservist's medical care is taken care of by the military during active duty, but dependents must wait 30 days before going into the military's Civilian Health and Medical Program for the Uniformed Services, where specified doctors provide their care, said a Defense Department spokesman.

Some employers have decided to amend their policies to help reservists during this crisis, however.

Inova Systems -- which includes the Fairfax Hospital System as well as local nursing homes and emergency care facilities -- will give reservists two weeks' extra pay once they leave and extend all health benefits indefinitely.

Prince George's County will give 15 days' paid military leave and will pay both employee and employer costs of continuing health benefit coverage.for the duration of the Persian Gulf crisis only, the company is trying to "sweeten" the wage-differential and child-care segments of the company's military-leave policy.

MCI will continue all health benefits for employees and extend pay for up to four weeks.

"You have to have a fair and equitable transition plan," MCI's Zimmerman said. "rather than just wave a flag and wish them well."

Staff writers Stephanie Griffith, Jon Meacham, Pierre Thomas, Patricia Davis, Veronica T. Jennings, Retha Hill, Beth Kaiman, Richard Tapscott, Avis Lester-Thomas, Gabriel Escobar and Brooke A. Masters contributed to this report.