There is a new realism developing about belonging to a health maintenance organization.

Some HMO members call it disappointment.

Many -- just over half of 460 area readers who wrote us in recent weeks -- are wholly or mainly satisfied with their HMO. But about one in 10 has mixed feelings, and just over a third are wholly or mainly dissatisfied.

Like people who go to other doctors, many HMO members are finding they must look out for themselves. They often must ask for, and sometimes demand, the care they believe they have coming. They sometimes must fight for it.

HMOs nonetheless work for many people. And for some people more than others. They seem to have learned to "work the system." They have usually read the plan's literature and promises and know what it can do and what it won't do.

This is not getting easier.

Not a dozen years ago these prepaid practice organizations -- you join them and get all or most of your medical care for so many dollars a month -- were touted by some of their promoters as the solution to all our medical problems. They would -- I oversimplify but not much -- provide high quality medical care, with access to first-class specialists when needed, for a reasonable monthly sum, with no unexpected bills and no paper work.

Sometimes they do all these things. Sometimes, it is now obvious, they do not.

All these plans, old and new, are getting bigger, more competitive with each other and, for this and other reasons, more cost-driven and more careful -- some patients would say stingier -- about spending money on expensive forms of care.

Still, some people survive. And some thrive. Among members of every plan, some say, "I love it," some, "I hate it."

How can an individual learn to survive and possibly thrive?

Here are some comments, most of them from satisfied or largely satisfied rather than dissatisfied, members of Washington's 50-year-old Group Health Association members. They are typical of comments from all HMOs:"Part of my experience was having to learn my way about this large organization and realizing what everyone knows, that not every doctor is good for every patient, whether in or out of an HMO. After a few minor disappointments, I found the right doctor for me.""You sense some doctors are too aware of the clock. The smart patient writes up all his concerns and symptoms before seeing the doctor.""Getting second opinions for serious ailments is not mentioned or even encouraged. The informed, educated patient is the one who can be sure of optimum care.""You do often have to be demanding to get the full, complete treatment and not just rushed through.""For the best attention, speak out.""Group Health is good where they are alleged to be good. Many tests and treatments to avoid hospitalization. Free annual physical examinations, but only if requested and scheduled by the patient. Doctors make no follow-up to schedule needed visits. There is much available, but only on a demand basis.""A staff model HMO member must be assertive, aggressive and be willing to fight for her rights. Anyone lacking the ability and/or interest to do so will be sorely disappointed . . . The member must be able to read and understand all the restrictions (hospitals, co-payments, number of visits allowed) in their benefit package."

And from some Kaiser members:"To find the right doctor in an HMO takes time and patience. But to find the right doctor outside an HMO also takes time and patience.""The key is to follow the advice to choose a personal physician and to be assertive in dealing with the advice line" -- the "advice nurse" a patient reaches on the phone. "The lesson is, always see the same physician" -- though, said this patient, you may be kept waiting "for hours," a fact "I do not like, but deal with.""As with any insurance, you have to know what your coverage is and make them correct any errors, etc. HMOs are not for timid people who feel they can't question what is being done or not being done." ::

One of the main complaints of members of all HMOs is that their primary care doctor is their "gatekeeper." This doctor must make most referrals to specialists and well may not do so if it seems unnecessary -- or too expensive.

Many patients report seeing a specialist anyway by insisting.

Other have come to realize that going from doctor to doctor can have disadvantages, too. It costs the plan more. It sometimes costs the patient more. It may lead to unnecessary testing or treatments. And there is no medical procedure without possible risks.

"Health care costs need to be contained, and I don't mind having a limited choice that still provides quality care," wrote Kaiser member Laurine Gibson of Laurel.

An HMO's "coordination of care" -- deciding what doctors you should see and not see -- is "one of the greatest boons of joining an HMO," wrote Columbia Medical Plan member Sherry Peruzzi of Columbia.

Many people, she said, regard the fact that they must see a primary physician to be referred to a specialist as "a major drawback" and "want to consult with a variety of specialists directly, without 'interference.' " But the ordinary patient, she said, might select the wrong specialist, one who might find " 'nothing wrong,' which is what happened in my case when I consulted an orthopedist for what turned out eventually to be arthritis." :: :: ::

A satisfied George Washington University Health Plan member -- who is also an insurance coordinator at a large law firm that offers a choice of seven health plans -- wrote:

"From an administrative standpoint, the biggest headache is that some people enroll in an HMO without the slightest idea of what they are getting into. Especially bothersome are those who like the idea of 100 percent paid care but continue to use an emergency room as a doctor and find that the HMO comes back with warnings and, if repeated, failure to pay the emergency room bill.

"There are also complaints about long waits for appointments, and sometimes about being seen by nurse practitioners or doctor's assistants instead of a doctor . . .

"I think that most HMO brochures are informative. Member handbooks are in all cases excellent. The problem is, of course, that people don't read them."

Still, she reported, "on the whole, people are satisfied."

I'm sure she advises them, "Read all the literature."