Sen. Edward M. Kennedy, the AFL-CIO and 64 more national groups endorsed a cradle-to-grave health insurance plan for everyone yesterday and urged President Carter to honor his campaign promises by backing it.

In a Senate Caucus Room jammed with supporters, the Massachusetts Democratic senator said "all these constituencies" - unions, teachers, nurses, senior citizens, consumer groups and others - were sending Congress and the administration "a message."

The message, he said, is that "health insurance will be an important area" when people pick their 1980 presidential nominees. On balance, he also said, he himself will still support Carter for reelection.

None of the insurance plan's supporters said they would do otherwise, but some used far blunter language. Some accused the administration of preparing to support legislation that would pay mainly for catastrophic illnesses, those that exhaust ordinary private health insurance.

"I understand this present administration is dickering around with (this) kind of no-help bill," one offering "nothing" to the poor, near-poor and aged, said William Hutton, exective director of the National Council of Senior Citizens.

The president has not fulfilled his election campaign pledges to enact health insurance for all, "and we must go our own way," said AFL-CIO SECRETARY-TREASURER LANE KIRKLAND.

THE PRESIDENT HAS REPEATEDLY SAID RECENTLY THAT HE STILL FAVORS SUCH INSURANCE BUT THAT THE NATION CAN CURRENTLY AFFORD ONLY A "FIRST PHASE" TOWARD THAT GOAL - TO BE EMBODIED IN A BILL HE HAS NOT YET COMPLETED.

WHAT KENNEDY AND A NEW COSPONSOR - REP. HENRY WAXMAN (D-CALIF.), CHAIRMAN OF A HOUSE SUBCOMMITTEE - OFFERED YESTERDAY WAS A "HEALTH CARE FOR ALL AMERICANS ACT" THAT WOULD ORDER EMPLOYERS TO BUY ADEQUATE HEALTH INSURANCE FOR THEIR WORKERS FROM ONE OF SEVERAL NEW GROUPINGS OR "CONSORTIUMS" OF PRIVATE HEALTH INSURORS.

EMPLOYES WOULD CONTRIBUTE UP TO 35 PERCENT, UNLESS THE EMPLOYER CONTRIBUTIONS WOULD BE GEARED IN PART TO WAGES, AND WELL-OFF EMPLOYERS WOULD PAY MORE THAN LESS AFFLUENT ONES FOR THE SAME LEVEL OF BENEFITS.

LIKE THE CARTER PLAN, THIS ONE WOULD TAKE FULL EFFECT GRADUALLY, WITH A FIRST PHASE STARTING IN 1983 AT EARLIEST. BUT THE ENACTING LEGISLATION WOULD MANDATE ALL THE SUBSEQUENT PHASES.

FROM THE START, TOTAL PAYMENTS TO DOCTORS AND HOSPITALS WOULD BE NEGOTIATED IN ADVANCE EACH YEAR ON A STATE OR AREA BASIS.

ONLY BY ENACTING TOTAL COVERAGE, AND PUTTING AN ANNUAL LIMIT ON THE PAYMENTS, CAN THE NATION AFFORD HEALTH CARE AT ALL, KENNEDY SAID. HE PRESENTED FIGURES INDICATING THAT, FIVE YEARS AFTER HIS PLAN BEGAN, THE NATION'S PUBLIC AND PRIVATE HEALTH BILL WOULD BE $38 BILLION A YEAR LESS THAN IF NO SUCH LAW AT ALL IS PASSED.

TODAY, HE SAID, THE FEDERAL GOVERNMENT SPENDS $51 BILLION A YEAR FOR HEALTH CARE, AND STATES AND THE PRIVATE SECTOR SPEND $120.4 BILLION. UNDER HIS PLAN, HE SAID, THE GOVERNMENT WOULD SPEND $28.6 BILLION MORE, THE NONFEDERAL SECTOR $11.4 BILLION MORE, BUT A "CROSSOVER POINT" - WHEN THE NEW PLAN'S CONTROLS STARTED SAVING MONEY FOR ALL - WOULD BE REACHED IN FOUR YEARS.

WAXMAN ARGUED THAT, WITHOUT THIS PLAN'S FIRM CONTROLS, "PRESENT BENEFITS WILL BE ERODED AND HEALTH COVERAGE WILL SHRINK RATHER THAN EXPAND."

KENNEDY AND THE AFL-CIO leaders were backed too by an array of congressional supporters, among them Sens. Harrison Williams (D-N.J.), Jacob Javits (R-N.R.) and Lowell Weicker (R-Conn.). Senate Majority Whip Alan Cranston (D-Calif.) will also be a cosponsor.

Health, Education and Welfare Secretary Joseph A. Califano Jr. said he welcomed the bill's introduction but a health bill needs even broader support to have any chance. "The most heartening thing," he said, is that "everything is moving" and "there is a lot of interest in the Congress" this year in passing a more limited health insurance bill.

Kennedy conceded that the path for his plan will be "uphill," but called its passage "inevitable."

In previous years, Kennedy and labor backed a plan in which the federal government, rather than private firms, collected payments - taxes - from employers an individuals and paid out the benefits. The new plan, relying mainly on the private sector, was drawn up by a study panel headed by emeritus professor I.S. Falk of Yale, "architect of Social Security" in the federal government of the 1930s. CAPTION: Picture, Joining Sen. Edward M. Kennedy in sponsoring employer-funded cradle-to-grave health insurance, from foreground: Benjamin Hooks of NAACP, Sen. Donald Riegle (D-Mich.), Sen. Claiborne Pell (D-R.I.) and Rep. Henry Waxman. By James K. W. Atherton - The Washington Post