SERIOUS ILLNESS is a double ordeal for the elderly. The worst is of course the illness. But a close second is the incomprehensible stream of bills and insurance forms that follows. The problem is not just paying the daunting amounts involved but understanding what to make of those bits of urgent paper and how to keep track of and respond to them all.

No ordinary person recently ill can do it; this is a job for a CPA, not a convalescent. A first complication involves billing practices. Most doctors and other providers of services submit their bills directly to Medicare. But some don't -- and some who do send you, the patient, an informational copy anyway. Which to pay and which to ignore? In a complex case the patient may not know or even be aware of having been seen or of having been the subject of a test by some of the doctors or firms that dun him.

It is only a little better -- some might say worse -- when Medicare then sends what it is pleased to call its explanations of benefits paid. Perhaps 400 million of these are now sent out a year; they are one of the commonest forms of communication between the government and its citizens. For all the undoubted effort made to keep them simple, they too can be baffling. They note that the doctor billed for X, but Medicare allowed only Y; that it then paid by law only 80 percent of that; and for the last year or two, for budget reasons, not even the full 80 percent, either. The patient is left with a balance, and if he has supplementary insurance, as most do, he will then start submitting claims and awaiting responses all over again. Meanwhile, the doctors and other providers understandably want to be paid; their bills keep coming in. If the patient has meanwhile gone back to see the same doctor, which visits are the bills for -- the old or the new?

It's torture, and there has to be a better way. The government is now taking a needed small step toward simplification. As of Saturday, all doctors will have to submit their bills first to Medicare. The American Medical Association objects to the burden, but most doctors already assume it, so it's not that sharp a turn. The next step should be to require that, where patients have secondary insurance, the bill be submitted directly to the secondary insurer as well. Whatever residual bill was then finally sent to the patient would be real and comprehensible.

An objection might be that this is an invitation to imaginative billing, since the insurers don't know what services were performed; only the patient does. But particularly in a complex case, the patient offers scant protection; he often doesn't know, either -- may know even less than the insurer. Let the doctors (and other providers) deal with the insurance computers; that's what basically happens anyway. The patient can deal later with the winner and in the meantime -- who knows? -- perhaps even recover.