Most of the government's 150,000 mid-level supervisors and managers would have to hustle more each year to qualify for full pay raises under a compensation package being studied by the Carter administration.

If approved, it would mean that thousands of supervisors and bosses each year could get smaller percentage pay raises than their subordinates.

The proposal, now before federal agencies for comment, is part of a sweeping bureaucratic overhaul plan. It is being developed for President Carter - who has generally approved the outline - by the Civil Service Commission and Office of Management and Budget. The final version of the plan will go to the President this month and the portions of it that he likes will be sent to Capitol Hill as a legislative package in March.

One of the key items in the package is a plan to eliminate full, automatic October pay raises for government supervisors and managers in the Grade 9 to 15 ranks. Those jobs now pay from $15,000 to $40,000 a year, and involve supervision of office staffs, work teams or as overseerers of work production.

Federal supervisors, along with rank-and-file workers, now get automatic catch-up-with-industry raises each October that reflect not only cost of living but changes in private sector pay.

Under the plan, designated supervisors (estimated to number up to 158,000) would be removed from the "automatic" features of the annual salary increase, and also from the near-automatic longevity increases government workers get every 1, 2 or 3 years.

In place of the automatic raises, the supervisors would be rated by their bosses and given either the full share, or a portion, of the annual percentage increase other government white collar civilian and military personnel get.

Similarly, to get incentive increases, which are not virtually automatic, the managers would have to earn them through performance.

Under present law, federal workers now get the longevity increases if, in the estimation of their supervisors, they have maintained in "acceptable level of competence" in their jobs. Different awards are given for outstanding work. Less than 2 percent of the employees who come due for the longevity raises, worth 3 per cent, are denied them now.

Key White House aides say that it is "indefensible" to operate a costly system that gives extra financial rewards to people who are "merely doing satisfactory work." They would like to end the automatic nature of the raises. If the President agrees, as expected, they would start with the Grade 9 through 15 managers and supervisors.

Under the plan, the management people would be given a portion of the annual catch-up-with-industry raise that would go to their subordinates. To get the full amount, or a bonus, they would have to earn it through performance.

The full civil service reform plan, as reported here Tuesday, has gone to agencies for comment. A top Civil Service Commission official confirmed that it does nto now contain any "major" changes in the federal pay system, or in the labor-management program.

But the "reform" package does include the important recommendation that supervisors and executives be taken out of the automatic annual and longevity pay cycles, and put on a systrem where future raises are based strictly on performance.