IT'S THAT TIME again. As the 95th Congress gives way to the 96th, a new crop of Washington lawyers is being created from those representatives and senators who either retired voluntarily or lost their bids for reelection.

Although some plan to return to the home states, a good number will keep Washington as the main base for a new legal practice.

Sen. James Abourezk (D-S.D.), for instance will join the small Washington firm of Shack & Mendenhall, which will be renamed Abourek, Shack & Mendenhall. Abourezk will also open an office with his nephew in Sioux Falls, S. D. Like most senators and representatives, Abourezk has refused to speak to potential clients until his term is up Jan. 1.

"People are approaching me, but I won't talk to them until I get done," he said. "Right now I don't know who's going to come in the door and hire me. I might even starve if no ones comes" -- but he doubts that.

Although Abourezk -- the only Arab-American in the Senate -- has strong ties with the arb world, he said he isn't looking to pick up clients from among the oil-rich middle eastern countries. Nor does he want to become a lobbyist masquerading as a lawyer.

"I used to be a damned good trial lawyer until I got into politics and I'd like to do that again," said Abourezk who retired after one term in the Senate.

Another retiring senator, James B. Pearso (RKan.), is joining the Washington office of the New York firm Stroock, Stroock & Lavan, ranked among the 100 largest in the country.

In addition, Person will keep his ties in his home state by lecturing and teaching at the University of Kansas.

Sen. Carl T. Curtis (R-Neb.) also will join a Washington law firm but he has refused to name it because of the conflict problem.

Although Sen. William D. Hathaway (D-Me.), who was defeated in November, is telling callers he has not decided what he will do, aides report he is planning to practice law in Washington.

On the House side, Paul Rogers (D-Fla.), known as "Mr. Health" for the expertise he gained in that field as chairman of the House health subcommittee, is planning a washington law practice. He will announce on friday the name of the firm he will join.

Rep. Walter Flowers (D-Ala.) said he still has not decided whether he will practice law in Washington or Alabama, but his fellow House Judiciary Committee member, Rep. Charles E. Wigging (RCalif.) said he is returning to his home state to practice.

Sen. John J. Sparkman (D-Ala.), retiring after 28 years in the Senate and 12 years in the House, said he is going back to Huntsville, Ala., to set up a law firm with his grandson, Tazewell T. Shepard III, who now is in his last year at the University of Alabama law school at Tuscaloosa.

Wanna bet that will be one new firm not lacking clients?

Virginia's Sen. William Scott (R) will join the Springfield firm of Foldenauer, Maddigan, Scott & Scott (those are his two sons, Paul and William Jr.) when his term ends.

Will that bar ever stop revolving? The D.C. Bar's Board of Governors spent 3 1/2 hours Tuesday thrashing over proposed rules designed to make it harder for lawyers to use the revolving door between government and private practice.

And the Bar officials never got to the most controversial issue, which comes up this afternoon -- the third long session they have devoted to the subject.

The rules coming up this afternoon would disqualify entire law firms from taking cases in which one firm member was involved while working for the government. Unless a special waiver is granted.

Here is a quiz on ethics that is worrying thoughful lawyers, government officials and corporate executives across the country:

What does a lawyer do when he finds officers of a corporation he represents -- the very men who hired him and pay his bills -- acting illegally? Does he tell them to stop? Close his eyes to it all? Or does he report it to the corporation's board of directors?

Who, in fact, does the lawyer owe allegience to -- the people who hired him or the stockholders who really own the corporation?

These disturbing questions were thrust in front or the Securities & Exchange Commission by Georgetown University Las Center's Institution for Public Representation, which said the regulatory agency should require lawyers to report any fraud they uncover to the company's directors, who represent the stockholders.

"Too often the corporate lawyers don't even define the dilemma for themselves. They just fall into lockstep with the chief executive officer," said Charles H. Halpern, the institute's director.

Short takes: William E. Leonard, chairman of the International Trade Commission until 18 months ago, joined the Washington firm of Busby & Rehm as a partner. James Taylor Jr. has moved from associate to partner in the same firm... The first seminar on all the litigation expected to flow from the new energy laws is schefduled for Houston on Jan. 25-26 with a follow-up engagement in Washington on Feb. 7-8. The seminars are run by Legal Times of Washington and Harcourt Brace Jovanovich, and the conference chairmen are Gaynell C. Methvin of the Department of Energy, Dennis G. Linder of the Department of Justice and and Warren Belmar of the Department of Justice.

Switches in Maryland: Wayne N. Jesin leaving Fredericks, Jersin & Philo of Rockville to join the Silver Spring firm of Times & Salter as head of its real estate depatment an administrative partner. Also joining that firm: Miller S. Redden, who left White & Redden of Rockville... Miller Washington attorney Joel D. Joseph challenged Virginia and Maryland residency requirements for attorneys who want to take the bar exams there. He told the Federal Trade Commission the requirements are designed to lessen competition.