When Congress returns from vacation July 12, committees will get down to the business of implementing the new budget that calls for fewer federal workers, smaller U.S. pay and pension increases and a plan to put a new bite on civil service paychecks in 1983.

The budget puts a 4 percent limit on each of the next three U.S. pay raises due this October, in 1983 and October 1984. It also caps cost of living (COL) raises for federal and military retirees at 4 percent a year for March 1983, 1984 and March 1985.

In addition to capping salaries and annuities, the budget proposes a 2 percent cut--between 40,000 to 50,000 jobs--in federal employment over the next several years. That would be on top of the nearly 40,000 drop in federal employment that has taken place since President Reagan took office.

Congress is also working on a plan that would, if it becomes law, force federal and postal workers to help pay for Medicare. They would be required to contribute 1.3 percent of salary (up to the first $35,000) beginning next January to finance the Medicare portion of Social Security.

Although friends of federal workers may be able to head off the Medicare proposal this year, there is little chance that committees of jurisdiction will be able to find a way to give employes or retirees raises of more than 4 percent over the next few years.