Max I. Richtman, a slim, 6-foot lawyer, was bounding up the steps from the Capitol basement when he got a glimpse of Sen. Paul Simon (D-Ill.), ducking down one of the ornate halls outside the Senate chamber.

In an instant, the hunt was on. "Senator Simon, Senator Simon," Richtman shouted. "Max!" responded the senator, turning to recognize Richtman, chief lobbyist for one of the country's largest -- and most controversial -- senior citizen groups.

Richtman wasted no time, quickly telling Simon his group was troubled by rumors that Republicans were plotting income-related premium boosts for Medicare.

Not to worry, Simon sought to assure Richtman. Most senators don't want to change the premium system. "I think it has a broad base of support," said Simon, who is up for reelection this year.

The encounter lasted no more than three minutes, but for Richtman it was enough. He had met the two criteria he laid out for himself when he made a late-afternoon lobbying run on the Hill: He had been "visible" and he had pressed his employer's latest worry on a senior legislator.

Richtman works for the National Committee to Preserve Social Security and Medicare, the group that gained influence on Capitol Hill last year when it led the fight to repeal the Medicare catastrophic-illness insurance plan.

The group -- which raises $40.5 million a year through a direct-mail campaign -- says it intends to ensure that the current budget crisis does not end with increased Medicare costs for the nation's senior citizens.

"Our goal is to do whatever we can to bring fairness into this budget solution," Richtman said in an interview in his gray K Street office as he kept glancing at a television set tuned to the House proceedings. Fairness, Richtman explained, means opposition to any proposal that "singles out" senior citizens, making them bear a disproportionate share of cuts in federal spending.

Within hours of the collapse of the budget summit, the group moved with the speed and muscle that has earned it respect and condemnation. During the Columbus Day weekend, printers in Green Bay, Wis., were placing the first of 2 million first-class letters to committee members in the mail.

In the past, such appeals have produced tons of postcards -- all pre-addressed -- from the group's 5 million members to their legislators.

Richtman said he had no doubt it would work again this time. When he met with Sen. John S. McCain (R-Ariz.) last week, one of his first actions was to alert the senator and his staff that the cards would be coming.

The last such effort brought 4,000 cards to McCain's office. "These guys can burn the wires," said McCain, who once was one of the committee's critics and now has become one of its heroes.

Created in 1983 by James Roosevelt, son of Franklin D. Roosevelt, the president who helped found Social Security, the group had difficulty at first in getting its telephone calls to members of Congress returned. In 1987, members of a House Ways and Means subcommittee charged the committee was terrifying the elderly with exaggerated claims that the Social Security system was about to collapse. Others charged that "the Roosevelt committee" simply made mailings to raise money for still more mailings.

Infuriated by the committee's use of official-looking logos, Congress enacted a law that prohibited any group from using emblems or lettering that might suggest it was linked to Social Security. The law was aimed at stopping letters, frequently under Roosevelt's name, that some government officials said suggested Social Security recipients needed to pay the organization's $10 membership fee to keep government checks coming.

"They've taken a concern that needs no champion, frightened the elderly half to death and raised a lot of money out of it," Rep. Don Edwards (D-Calif.) said at the time.

Roosevelt denied the charges, but earlier this year he stepped down as the committee's chairman, citing ill health. Some committee officials say privately that while Roosevelt has had serious health problems, he also may have been "the fall guy" for an era of scary mailings that often distorted Social Security's problems.

Under its new president, Martha A. McSteen, former acting commissioner of the Social Security Administration, the group and its staff of 60 have won new credibility in Congress, McSteen aides say. When the committee produced a mailing about the plight of rural hospitals, Sen. Lloyd Bentsen (D-Tex.), sponsor of legislation on the issue, reviewed the letter before it was mailed.

Even so, traces of "the Roosevelt committee" remain. Letters still arrive at the committee addressed to James Roosevelt from individuals who want to share their fond recollections of his father. When Richtman showed up in a Senate anteroom Thursday afternoon, he was instantly greeted by a clerk as "Max Roosevelt."

Some members of Congress still refuse to deal with the committee. "I've had guys call me and say: 'I don't need you to interfere with my seniors,' " said Lloyd L. Duxbury, the former Republican speaker of the Minnesota House who serves as one of the committee's seven lobbyists.

Sen. Alan K. Simpson (R-Wyo.) has been among the most persistent critics. The Senate gallery broke out in laughter last week when Simpson said he could never agree with the committee "because they are never right."

Last year, the group broke with most of the nation's major senior citizen groups, which were backing Congress when the elderly began to complain about new fees for Medicare catastrophic-illness insurance. When Congress dumped the plan, it was widely seen as a major boost for the committee and a setback for the larger American Association of Retired Persons (AARP), which supported catastrophic-illness insurance.

In audited statements, the Committee says it raised $42 million in the year ended March 31. It says it spent $11.8 million of that on education, $12.3 million on lobbying, $9 million on administration and $7.8 million on fund-raising.

Interviews with the group's staff members, however, indicate that those numbers may mask the true costs of the mailings. The costs are determined on a paragraph-by-paragraph basis. The letter's addresses and signatures, for example, are charged to administration, paragraphs that deal with what Congress is doing are considered education, and only those that solicit funds are charged to fund-raising, according to the aide in charge of recordkeeping.

At the height of the controversy over the group's operations, some of its congressional critics charged that the mailings -- 22 of 28 in 1986, according to Rep. Robert E. Wise (D-W.Va.) -- were solicitations. The group's staff says all mailings now make clear that multiple donations are not necessary to remain a member in good standing with the organization.

In addition to seeking funds for its regular operations, the group also rents out its mailing lists and operates a political action committee. This year it will give about $1 million to congressional candidates. "No question that we contribute more to Democrats," Richtman volunteered. "They're better on our issues."

Part of the organization's effort to erase its old image as a purely fund-raising operation involves being visible on Capitol Hill. After his scheduled meeting with McCain, Richtman wandered the Hill for more than two hours, searching for a few words with any member he could find.

He chased Sen. Richard C. Shelby (D-Ala.) into an elevator in the Hart Office Building, winning assurance from him that the feared GOP changes were unlikely, but he was unable to find Sen. Tom Harkin (D-Iowa) to thank him for fighting for a proposal the group endorsed.

Richtman says he may attend 20 fund-raisers in a typical week and recently logged six breakfasts in one day. He goes, he said, because it is one place where he is certain to see one or two legislators.

On Thursday night, as he wheeled into a parking lot at the Democratic Club on Capitol Hill, he said: "This is where all the lobbyists end up every night. It's kind of depressing -- no windows."

Inside, Richtman, 43, who describes his salary as "less than six figures," grabbed a club soda, a small plate of pasta and made certain he was quickly seen by the two Democrats to whom the committee had given $2,500 each before he darted out of the room.

Earlier, as he wandered across Capitol Hill hoping he could catch a senator between roll call votes, Richtman paused outside the Dirksen Office Building and offered his nightly lament. "You always wonder how valuable this day has been: Has your message gotten across?"