Travel-assistance companies now are touting their programs to Americans going abroad later this year. The programs -- which are not sold by insurance companies -- have advantages for travelers, but anyone thinking of buying one of the plans should shop carefully to get the right package and to avoid duplication of existing insurance.

The advertisement, set inside a black box, begins with this headline:

"7,318 Americans Die While Traveling or Vacationing Abroad. Over 9,000 become ill enough to consider medical evacuation."

After citing the problems that can confront the traveler who gets sick in a foreign land and who may have to be medically evacuated, the advertisement goes on to suggest a remedy -- Health Care Abroad health insurance.

HCA is the newest of the travel-assistance programs to have sprung up in recent years. And its advertisement, which appeared in the Wall Street Journal in February, is the latest aimed at Americans planning to travel abroad this year. The program also are spotlighted in the literature available at travel-agent offices.

Other assistance plans now being promoted in preparation for the heavy summer travel season include NEAR (Nationwide/Worlwide Emergency Ambulance Return Inc.), International SOS Assistance Inc., HOME (Help in Overseas Medical Emergencies) and Assist-Card.

"The American public is ready to understand it [the assistance plans] . . . they are now aware of the need for it," said Jim Molini, general manager of Assist-Card, one of the oldest of the help companies.

"In the past, the travel industry didn't talk about anyone getting sick. They focused on young sexy people and palm trees. They didn't want to bring up the fact that something might happen on that trip."

Although the assistance plans vary significantly from one company to the next, all of them promise some form of help for the American who suddenly become so ill during an overseas trip that medical evacuation is necessary. Some programs also offer assistance during less major illnesses. The price for the help ranges from a low of $10 for some plans to a high of $120 for others.

The variety now available means that travelers will be able to choose the package most suitable for their needs. But it also means that the selection will require more time and thought.

For those who want to make sure they are protected during their travels abroad this year, there are three basic categories of help to consider.

Transportation programs which help pay the expenses whent he traveler needs to return home with special medial assistance, such as a stretcher. This is offered through such programs as HOME, SOS and NEAR.

Combination plans which help pay medical and transportation expenses. HCA and Assist-Card provide such benefits. NEAR officials indicated that their program soon may offer foreign hospitalization insurance as well as transportation home.

Traditional travel accident insurance coverage which is available through most insurance agents but which may not cover transportation costs home in event of a medical evacuation. An estimated 15 insurance companies now write travel insurance policies which can be purchased through many insurance agents and travel agents.

Because Medicare doesn't provide any benefits to American citizens when they are abroad, the older traveler should look carefully at extra coverage that would defray medical expense and transportation costs in event of an illness in a foreign country. (Medicare coverage does apply within the U.S. territories of Puerto Rico, the Virgin Islands, Guam and American Samoa. Medicare is valid in two other cases: when a traveler taking a direct route to Alaska becomes ill in Canada, and when a vactioner is stricken on the U.S. side of the Canadian or Mexican borders and the nearest available hospital is across the border.) Senior citizens already may have one of the "Medigap" policies which provide supplementary benefits at home and abroad. If not, they may want to consider one of the travel-assistance plans for overseas trips.

Regardless of age, all travelers should consider these three points when shopping for an assistance package:

None of the five firms selling assistance programs is an insurance company, and, therefore none of them is subject to state insurance regulation. Health Care Abroad, for example, is operated by an insurance agent and broker who writes policies for several companies, including Lloyd's of London. NEAR, HOME, SOS and Assist-Card sell memberships which entitle travelers to certain benefits.

Assistance program benefits may duplicate insurance that the traveler already has. To avoid unnecessary duplication, the traveler should talk to an agent or to an official familiar with the terms of the traveler's regular policy and then compare those terms with the assistance program benefits.

Some travel-assistance programs are so new that it is difficult to assess their performance records. The HCA program for the individual traveler has been operating less than six months. NEAR is in its second year.

Officials of some travel plans refuse to disclose information on the size of their business or on the number of cases where they have extended aid to members. Asked how many evacuations have been made by NEAR, for example, President Joseph Travis said "many, many." However, he would not divulge the number of evacuations or the number of members because "that is privileged" and he didn't want NEAR competitors to know.

In contrast to that, Assist-Card's Molini said that his organization has about 30,000 members. He said that about 40 percent of the calls to Assist-Card concern medical problems. The other 60 percent involve thefts and losses of valuables, passports, tickets.

The Assist-Card program, which started in Europe more than 20 years ago, has been available for sale in the United States since 1978. Its services for travelers are similar to the program that the American Automobile Association has its member motorists.

Armed with the Assist-Card and its telephone directory, the member can call for help 24 hours a day and reach someone who speaks English and who can assist with a range of problems -- medical, legal, financial.

"If the person is sick, they say where and what," said Molini. "If necessary, we will send a doctor and ambulance and provide hospitalization. We pay for those services up to $3,000 for medical service, up to $500 for medication. We pay for an accident up to $10,000."

Molini said Assist-Card also will pay for evacuation home of a sick member when it is determined by the organization's medical team to be necessary. "If the doctor thinks it would be best for the person to be in their home country, we would get them home. But if he thinks the best care for someone on a Greek Island vacation would be Switzerland, then we would do that."

In case of a legal problem involving an accident, Assist-Card will provide a lawyer, Molini said. In the case of an arrest, the organization provides the name of an attorney but doesn't pay for the legal expense.

The price for Assist-Card depends on the number of days that the traveler will be abroad: $20 for five days; $30 for 10 days; $40 for 16 days and so on. wThe organization can be contacted on a toll-free telephone number, (800) 221-4564.

While Assist-Card is the oldest of the help plans for the individual traveler, HCA is the youngest.

Organized originally to provide assistance for student tours, HCA began selling its program to individuals in October 1980. Tom St. Denis, the agent who operates the program through his agency, International Underwriters Inc., said it provides travelers with a 24-hour-a-day telephone-referral service and a directory of physicians and hospitals in more than 1,100 cities in 128 countries. The HCA identification card entitles the traveler to immediate medical attention from any of those hospitals or doctors. Without the card, the traveler would be liable for payment himself either before or after treatment.

The HCA program includes major medical insurance up to $10,000, medical evacuation up to $2,500 and up to $10,000 for accidental death and dismemberment.

St. Denis said the program costs $1 a day -- with a $25 minimum. HCA, which is based in Falls Church, has a lcoal telephone number, 790-5655. Anyone calling from outside Virginia can reach HCA on its toll-free number, (800) 336-3310.

Of the three medical-evacuation programs, NEAR probably has been the most aggressive promoter. Through its newsletter and brochures, distributed to thousands of travel agents and insurance agents, NEAR has attempted to spotlight the exasperating and expensive problems of medical evaucation from a distant point such as Tahiti or China.

NEAR maintains a 24-hour toll-free telephone information center to accept calls from members in trouble. "If they become seriously ill or injured, we would arrange transmission of the member's total medical history in the appropriate language," said President Travis.

The organization "guarantees" to bring its members back from anywhere in the world -- if the person is determined to be non-ambulatory in the judgment of the attending physician. Travis said that in some cases, the traveler would be brought back by NEAR even if the attending physician believes the person is ambulatory. For example, if the NEAR medical staff thought it best for the person to return on a stretcher even though the attending physician considered the person ambulatory, the person would come back on a stretcher, Travis said.

NEAR charges an annual membership fee of $62 for a single traveler and $86 for a family of travelers. The family membership covers both spouses and all children up to age 18. The toll-free number for the NEAR, based in Oklahoma City, is (800) 654-6400.

NEAR promises to return members to their homes, in contrast to the other two transportation programs. HOME says it will evacuate the person to the nearest suitable hospital, while SOS says it will evacuate the person to the nearest facility capable of providing the required care.

Headquartered in Geneva and Philadelphia, SOS provides telephone services to worldwide, monitored, multilingual network of medical centers and emergency hospital deposits. However, unlike NEAR and HOME, the SOS members or their employers are responsible for the cost of medical services and evacuations.

SOS membership costs range from $10 for one to seven days to travel to $120 for a year's agreement. SOS began offering services in 1966 in Europe and in 1976 in this country. The organization's toll-free number is (800) 523-4939.

The HOME program, with offices in Washington and Dallas, costs $12 a year and offers basic services including medical evacuation and physician services necessary in the diagnosis and treatment of an illness prior to evacuation. The HOME telephone number in Washington is 223-5996; the toll-free number to its Dallas switchboard is (800) 527-0218.

How do travel agents rate the assistance programs?

"Essentially, what we do is allow agents to make up their own minds," said a spokesman for the American Society of Travel Agents. "We don't endorse any one over any other.

"But we do try to encourage members to take seriously the idea of the client's health."