Sen. Edward M. Kennedy (D-Mass.) and top labor leaders, at odds with President Carter over national health insurance, have agreed to their own plan that would provide coverage to all Americans and clamp tighter controls on costs then anything proposed by the president.

The plan grew out of Kennedy's and labor's dissatisfaction with proposals issued by Carter in July that called for a program that would be phased in over a number of years and only if various economic conditions warranted.

The opposition plan, which Kennedy may unveil later this week, was approved unanimously yesterday by the executive committee or the laborbacked Committee for National Health Insurance, headed by United Auto Workers president Douglas A. Fraser.

Also present were Lane Kirkland, AFL-CIO secretary-treasurer, and representatives of consumer, farm, women's and nurses' groups, as well as other unions.

Kennedy plans to open hearing on the plan before his Senate health subcommittee on Oct. 9. On Oct. 25 he expects to start out-of-town hearings in Detroit, where UAW officials are concerned that the cost of health benefits will cut deeply into wages in future contracts.

This threat has made labor leaders eager to press the health insurance issue.

According to a text obtained by The Washington Post, the Kennedy plan lays out a specific combination of private insurance and federal payments to give the same level of benefits to the employed and unemployed, the poor and the elderly.

In another sharp departure from the President's present plan to phase in any new health insurance piece by piece as the economy and health costs permit, the Kennedy-labor plan would go into effect two years after Congress adopted it.

To afford this, however, a set of "limits" would go into effect immediately on both hospital bills and doctors' services. This temporary control on health costs would be accomplished by broad "budget caps": annual limits on rates of increase much like those so far unseccessfully sought by the Administration.

Then two years later, when the new plan's benefits took effect, a new Federal "Public Authority" would begin to work through 51 "State Authorities" - usually existing health agencies - to negotiate in advance with all hospitals and classes of doctors to set specific fees, rates and hospital budgets each year.

The ambitious goal would be to hold future cost increases in line with the inflation rate.

By holding costs down, the Kennedy plan's added cost to the federal budget - beyond the $36 billion currently paid for Medicare and Medicaid benefits - would be $18 billion to $20 billion in 1978 dollars.

In addition it was estimated, "around $5 billion" would have to be added to the approximately $45 billion that remployers and employes pay for health insurance.

"The key is cost control," said another proponent. The state of Maryland's powerful Health Services Cost Review Commission held hospital costs to a 7 to 8 percent increase in the year ended last June, while costs nationally rose 12 to 13 percent.

Then states already have similar bodies to negotiate hospital rates or approve budgets in advance in much the same way as the "prospective budget review" in the CNHI plan.

The plan was drawn up largely by CNHI technical committee headed by I.S. Falk. Yale professor emeritus who, as Social Security Administration research director, helped lead the fight for government health insurance for many years.

Among the plan's features:

Private health insurers - commercial or Blue Cross-Blue Shield - would have to be "certified" as providing equal benefits to all without excluding anyone for age or previous illnesses.

The insurers would have to belong to "consortiums" to help negotiate hospital and medical fees.

Under a scheme of "earnings-based premiums," some low-paying employers could pay less than others and some high-paying employers could pay more.

The federal government would pay the costs of insurance for the poor and the unemployed, as well as some of the costs of lowearners any poor or unemployed citizen could join any certified insurance or prepaid medical plan.