The Carter administration has promised that federal agencies will not be overloaded with political appointees if Congress passes the pending civil service reform bill. It is designed to streamline hiring and firing in government, create a new produce-or-perish executive corps, and generally make bureaucracy more responsive to the White House.

Part of responsiveness centers around a Senior Executive Service. Eventually it would take in the 9,200 eareer and political executives who run government on a daily basis.

Under the SES, newly appointed Grade 16 and above persons would be forced to join. They would be subject to new hiring standards, easier dismissal or demotion and more frequent transfers. SES members also could get five-year bonuses worth up to $5,000 a year, and be eligible to earn bigger pensions and earlier retirement.

If Congress approves reform and the SES, incumbent "supergraders" would have the option of joining up or remaining in their current career status. Those who decide to remain out, it seems fairly obvious, would probably be cutting themselves out of consideration for future promotion.

Administration officials charged with selling reform have guaranteed in the proposed law that no more than 10 percent of the SES members would be politicial appointees. And they have pledged that under SES the political makeup of an agency's work force will not exceed 25 percent or the current percentage, whichever is greater. The ratio of 90 percent career to 10 percent political executives would remain governmentwide, according to written assurances the White House has given Congress.

Unless a hitch develops - over something like the politically explosive proposal to eliminate veterans preference - Congress should begin voting on the reform plan within a month or so. Both the Senate Government Affairs Committee and House Post Office-Civil Service Committee have completed hearing on reform. Next step is the bill-writing, and horse-trading among various pro-and-con pressure groups interested in the Carter reforms.