WHEN HE RETIRED from the Air Force in 1977, Col. John Abell enrolled in something called the survivors benefit program. The idea was that he would pay a certain amount of money each month to guarantee that if he died first his wife would receive 55 percent of his retirement pay for the rest of her life.

But Abell and his wife, Nancy, are separated now and they have discovered that should they divorce, she will no longer be eligible for survivors benefits. "The law does not provide for that survivor's benefit protection to be continued even if both people wish to do it, which seems somewhat unreasonable to me," says John Abell. "I would like to do it in my own case," he says, "and not being allowed to is sort of annoying."

The survivors benefit program is the latest in a series of military benefits that former spouses are trying to get Congress to reform. Hearings are scheduled today on bills that would allow retirees to assign benefits to an ex-wife as well as to divide them between spouses, and on bills that would allow former spouses to receive automatically a pro-rated share of the military person's retirement.

Ex-wives of military personnel have in the past testified on behalf of legislation that would allow them to continue being covered under military health plans. As the law stands now, these women after 20 and 30 years of marriage, lose their military health coverage when they are divorced and they are often too old or too ill to qualify for civilian health insurance plans.

If the spouse in the military remarries -- even if he is retired -- the new spouse automatically becomes eligible for these medical and survivors benefits, even if she has put no time into the spouse's military career. That, according to a number of organizations for former military wives that are springing up across the country, is unfair. John Abell agrees.

"It seems to me that some of these entitlements rightfully, at least in the moral sense, belong to the first wife. In the case of my wife, we had been married 23 years. She had those benefits all of her adult life. She was married to a military person throughout his career until his retirement. It doesn't seem unreasonable to me that she be afforded those benefits even after divorce."

Military wives, says John Abell, put up with an awful lot." "Military families are constantly moved when they don't want to. Until recent years, at least, they heven't ever been able to make any money on housing. There just are all kinds of problems with being in a military family that are induced by the frequent relocation. The children pay a considerable price for that as well.

"The military wife put up with some undesirable circumstances, some hardships she might not put up with as the wife of a civilian," says John Abell. "It doesn't seem unreasonable to me to extend to such women something like medical insurance. I don't see how people could argue strongly against that."

The Defense Department is arguing strongly against it, saying medical coverage for ex-spouses could cost as much as $45 million a year.

But allowing the survivors' benefits to be assigned to former spouses or prorated between spouses, and prorating retirement benefits to ex-spouses would entail nothing more than the administrative costs. And, as Rep. Patricia Schroeder, (D-Col.) who is sponsoring legislation to do this has pointed out, it might keep some of these former military wives off public assistance rolls, where some of them are ending up.

Schroeder's legislation would make the survivors benefit program mandatory unless waived by all spouses involved, and would give the ex-wife a prorated share of the retirement if she has been married to a military person 10 years or more. The bill "acknowledges that the pension is an earned benefit of the wife as well as the husband," says Andrea Pamfilis, a legislative aide to Schroeder.

Nancy Abell is president of a new organization called Ex-Partners of Servicemen for Equality, which was formed to lobby Congress on behalf of fomer military wives. She says she is "very fortunate. . . . I will be getting a good amount of support," from her husband. But, she says, "some of the ways these men have left these women and ended the marriage are just atrocious.

"We feel these men could not have advanced in their careers if we hadn't been watching the home front and raising the children, often while they're overseas, and it's kind of a blow when they turn around at the end of their careers and prefer some younger woman to you."

Former wives of military and of Foreign Service officers argue that because their husbands' careers required them to move frequently they were unable to pursue their own careers. Then when they are divorced, they end up with no career and, often, no dependable source of support.

Their chief opposition in their quest for benefits is coming from organizations of military officers. An amendment that would have allowed ex-spouses to receive a share of the Foreign Service officers pension was recently defeated in committee by one vote. Abell says her organization will be meeting soon with Foreign Service wives to exchange ideas.

"We get letters constantly from women who are welfare cases, women with terminal illness who have no medical coverage," says Nancy Abell. "There are a lot of desperate women who are really fearful for the future.

"Younger women are having a chance to get educated about all of this," she says. "Wives are refusing to give up their careers. The younger men are leaving the service rather than accepting the transfers. Had we known 20 years ago what was going to be happening to us, we might have said, 'Hey, we're not leaving our careers.'"

"But," she says, "our career then was supporting the military men. The younger women now are smart."