Beginning in March, federal workers may be a new, combination insurance package that will raise the life insurance policy of the "typical" $20,000-per-year civil servant to $138,000. That employee currently is limited to a maximum goverment policy of $33,000.

A series of four insurance options -- two of them new -- will be offered U.S. workers effective April 1. They will have the entire month of March as an open enrollment period to decide which insurance options, if any, they want.

Top-paid federal workers, now generally limited to a maximum $73,000 policy, will be able to purchase a combination policy through the government that will increase their total life insurance face-value policy to $378,000. Rates, of course, vary by age and with the options selected by employes. The new insurance program, originally sponsored by Rep. Gladys N. Spellman (D-Md.), also will permit government workers to buy a $5,000 life insurance policy on their spouse and $2,500 in life insurance for each eligible child under age 22.

For the under-35 federal workers making $20,000 per year, the cost of the maximum $138,000 insurance package will be $11.37, deducted from his paycheck every two weeks. For the employe age 55-59 at the same salary, the same insurance package would cost $75.75 biweekly.

Payments for accidental death for the $20,000-per-year, under-35 worker now amount to a maximum of $66,000. Under the plan that goes into effect April 1, the same individual's accidental death benefit payment would be $171,000.

The new benefit package will raise accidental death benefits (now $146,000) for top-paid workers to a new level of $451,000.

To purchase any of the new or existing optional insurance packages, federal workers must enroll, or reenroll, in the basic insurance plan that covers 2.5 million employes. Even if you already have insurance, you must reenroll during the March 1-31 period.

Cost of basic insurance (formerly called regular insurance) will be reduced effective April 1 from the present 25 1/2 cents biweekly per thousand to 24 cents. Beginning in October 1981, basic insurance for eiligible employes under age 45 will be raised at no cost to the worker. Increases will be graduated by age with those under age 36 getting twice the current amount. Here are the new rates for the various options. Remember, you pick them in March and they go into effect in April.

Option-A, Standard Insurance: This is a $10,000 optional package available to anyone with basic-regular insurance. Beginning April 1, rates for the under-35 crowd will be 60 cents biweekly; 80 cents per day period for those age 35-39; $1.40 biweekly for those 40-44; $2.20 for those 45-49; $3.20 for those 50-54; $7.50; $7.50 biweekly for those 55-59 and $9,00 biweekly for those 60 and over.

Option-B, Additional Insurance: Employes can buy this additional coverage in multiples of from one from five times his or her annual base pay (rounded to the next higher thousand dollars) Those rates, effective April 1, would be: Five cents biweekly per $1,000 of coverage for persons under age 35; 7 cents biweekly per $1,000 of coverage for those 35-39; 12 cents for those 40-44; 20 cents for those 45-49; 30 cents for those 50-54; 60 cents for those 55-59 and 95 cents biweekly per $1,000 of coverage for those 60 and over.

Option-C, Family Coverage: provides $5,000 for the husband or wife of the federal worker, plus $2,500 for each eligible child under age 22. Those rates will be: Fifty-cents biweekly for persons under age 35; 60 cents for 35-39; 70 cents for those 40-44; 90 cents for those 45-49; $1.30 biweekly for those 50-54; $2 for those 55 through 59 and $3 biweekly for persons 60 and older.

Office of Personnel Management, which worked out the guidelines for the new insurance options in line with the new Spellman Act, will be supplying details of the program to federal agencies in time for the March enrollment period. The new insurance benefits available April 1 could convince some federal workers, who had been planning to retire, to stay on.