Here's a sneak preview of various merit pay systems federal obsses will soon be using to set pay raises for hundreds of thousands of mid-level government workers.

In metropolitan Washington alone, 65,000 people in Grades 13, 14 and 15 will be put under merit pay this year, or by October 1981 at the latest. They will no longer get automatic longevity raises. Nor will they be guaranteed the full amount of regular October catch-up-with-industry adjustments other white collar feds get.

The civil service reform law requires departments -- with approval of the Office of Personnel Management -- to set up merit pay systems tailored to their particular needs. Under merit pay, employes get only half the regular October raise unless bosses grant them more for above-average work.

Merit pay rating systems will vary by agencies, but they fall into three general types. So far OPM has okayed only two merit pay systems, the one it will use and one cleared yesterday for Commerce. Two other major departments -- Justice and Navy -- have submitted plans to OPM for approval. This is what they look like:

Navy will have a system with six evaluation categories. They will be:

(1) Substantially above target on all items.

(2) Substantially above target on most of significant items.

(3) Above target on all significant items.

(4) On target on all significant items.

(5) On target on most of the significant items.

(6) Below target on most of the significant items.

(The items are critical elements of job performance to be spelled out by each agency to each employer under merit pay).

Navy will set up a point system for each of the six categories. Points will translate into dollar raises (based on money in the individual merit pay pool for each grade). Everyone will get the same dollar raise, depending on number of points assigned his or her category.

Commerce has five categories: Outstanding, Commendable, Satisfactory, Minimally Satisfactory or Unsatisfactory. There will be three levels within each of the five categories. If the October raise for rank-and-file workers was set at 5.5 percent, employes rated minimally satisfactory or unsatisfactory could get only half of it. A GS 13 Commerce worker earning $31,333 would get a raise equal to 12.9 percent if rated outstanding. The same employe earning $33,291 would get 11 percent if rated outstanding. Someone earning $36,228 would get 10.1 percent for an outstanding rating. Those rated "commendable" would get 9.6 percent, 8 percent and 7.4 percent respectively under the complicated weighting system.

Justice has set up a hybrid system wit the same number of categories (5) as Commerce, but also using the point-dollar rating system of Navy. It will enable people at the lower end of Grades 13, 14 and 15 to get bigger percentage pay raises than those given the same ratings who earn more. The Justice plan was designed to help it provide faster rewards to bright young attorneys.

OPM has decided to use the Justice-designed system.

Health, Education and Welfare has not come up with a final system, but it is leaning toward an overall HEW merit pay plan that could be tailored to its different units.

Department of Transportation is also considering a general statement of "intent" on merit pay for the department, but one that would allow for different merit pay systems to be used in different components such as FAA and the Coast Guard.

So far, OPM is the only agency that plans to implement merit pay this October. Commerce has the capability, but plans to have a "dry run" this year, advising employes where they would have come out under merit pay, but keeping the regular October adjustment for everybody intact for 1980. It and other departments and agencies will implement merit pay in 1981.

American Federation of Government Employees has its executive council in town through Friday. Leaders of the big AFL-CIO union will talk about organizing legislation and finances.

But the sexy item for the 300,000-member union will be the question of political endorsements. Insiders expect a resolution today proposing that AFGE endorse Sen. Edward Kennedy (D-Mass.) for the Democratic nomination. Odds are the union leadership will head that off, keeping its options open until it can see what President Carter will offer.