President Reagan's new budget continues the turnaround on taxes he began last year, seeking tax increases that would add up to $11.2 billion in 1984, $11.3 billion in 1985 and $61.3 billion in 1986.

The largest of these in the first two years would come in Social Security taxes. Employer-paid health insurance premiums over certain amounts also would be treated as income and taxed for the first time. In the third year, unless the deficit is reduced more than predicted in the meantime, there would be an income tax surcharge and new excise tax on oil.

The tax increases are a reversal of the administration's initial drive to reduce tax burdens. In 1981 Reagan pushed to passage a bill reducing tax liabilities a total of $609 billion from 1982 to 1986. Last year, however, he supported two bills raising taxes a total of $163.1 billion over the same period, in effect taking back 27 percent of the 1981 cut.

If Reagan wins approval of all the new increases called for in the current budget, he will have raised taxes by a total of $246.9 billion for 1982 through 1986. In effect, he would have taken back 40.5 percent of his 1981 tax cut.

This take-back percentage also would rise as the years go on. Thus if all the new increases in the budget were to take effect, the net Reagan tax cut by fiscal 1986 would be just 42 percent of what was promised in the 1981 bill.

Federal revenues this fiscal year will be an estimated 18.7 percent of gross national product, one of the lower figures in recent years. But by fiscal 1986 they are projected to move back to 20.3 percent, which is about where they were when Reagan took office and the third-highest level since 1969, when Congress, at President Johnson's behest, approved a 10 percent income surtax to help finance the Vietnam war. That surtax lifted federal revenues to 20.5 percent of GNP. In fiscal 1981 and 1982, they were 20.9 and 20.4 percent.

No matter what Congress does, there will be a Social Security tax increase during fiscal 1984. Under existing law the Social Security wage base--that part of each worker's income to which the tax applies--will rise to $37,800 on Jan. 1, 1984. It rose from $32,400 to $35,700 this Jan. 1.

The Social Security tax rate on this base is 13.4 percent, paid half by employers and half by employes. Acting on the recommendation of his Social Security advisory commission, Reagan would raise this slightly next January.

Other tax changes proposed in the budget include:

* The two "contingent" tax increases which would be enacted this year, but would not take effect until 1986, and then only if certain conditions are met. The most important of these conditions is whether on July 1, 1985, the projected budget deficit for fiscal year 1986 exceeds 2.5 percent of GNP, just over $100 billion. The administration thinks it will exceed that figure.

The two taxes would be an excise tax on domestic and imported oil of about $5 a barrel, which translates into an increase of about 12 cents a gallon in gasoline prices, and an increase in income taxes of either 1 percent of taxable income or 5 percent of taxes regularly owed. These tax increases would raise about $46 billion.

* Employes would have to pay income taxes on employer-paid health insurance premiums in excess of $175 a month, or $2,100 a year, for a familiy, and $70 a month or $840 a year for a plan covering just the employe and not family.

This tax would go into effect Jan. 1, 1984, and raise an estimated $2.3 billion that year, growing to $6 billion by 1986. It is part of a broader effort to increase cost-consciousness in health care and reduce the medical inflation rate.

* Assorted proposals in addition to the rate speedup to increase Social Security revenues and contributions to civil service retirement plans. These would raise $9.4 billion in 1984, rising to $11 billion in 1986.

In addition, the administration is maintaining its support of a number of tax breaks which were not enacted during the 97th Congress, and the president is proposing two new ones. These are:

* Special Education Savings Accounts (ESAs). Taxpayers with adjusted gross incomes of less than $40,000 could put up to $1,000 a year for each child into special savings accounts. The maximum contribution would drop by 5 cents for each dollar of income above $40,000, so that it would phase out altogether for those making more than $60,000.

Money put into these accounts would be after-tax dollars; there would be no tax concession for making the deposits. But there would be no tax on any increase in the value of the account or on interest earned if, when ultimately withdrawn, the money was used to pay college expenses. This proposal would take effect Jan. 1, 1984. It would cost $100 million that year, and $200 million in 1986.

* Job credits for the unemployed. The administration is proposing a six-month extension of benefits for persons who have used up their eligibility for unemployment compensation. Recipients could choose, however, to have their extended benefits given in the form of tax credits to employers who hire them. This program would start on April 1, 1983, and end on March 31, 1984. It would cost the government $200 million in 1984 and 1985, and $100 million in 1986.

The administration also plans to revive its enterprise zone proposal, which would grant special tax breaks to businesses and certain employes in special zones to be designated in "economically distressed areas." It would cost $100 million in 1984, rising to $800 million in 1986.

In addition, Reagan again plans to seek approval of a tuition tax credit for parents with children in private and parochial schools. The maximum credit would be $100 in 1983, $200 in 1984 and $300 thereafter, with income limits the same as for Education Savings Accounts. If enacted, this would cost the government $200 million in 1984, rising to $800 million by 1986.

Finally, in an effort to encourage business activity in the Caribbean area, the administration will press again for a number of tax breaks and import incentives for the area. The revenue loss would be negligible.