The number one holiday shopping nightmare this year isn't taking place at the malls or the big-box outlets. It's at our senior centers, where Americans over 65 are trying to figure out which private health insurance plan to enroll in to get their prescription drugs paid for under Medicare's new Part D, which takes effect Jan. 1.

As seniors tell the tale, navigating the competing plans is no more complicated than mapping the human genome. In most states, Medicare recipients are presented with dozens of asymmetric options. The plans cover some drugs but not others, with discounts (or not) for generics. Some offer supplemental insurance to cover the gaping hole in the middle of the program (a patient's annual drug expenses exceeding $2,250 are not covered under the law, though coverage kicks back in once the yearly bill tops $5,100); some don't. Some plans re-price their options every day, a boon to seniors who want to make the selection process their life's work.

Simplicity may not always be a virtue, but when presenting life-enhancing and life-preserving choices to seniors, it's not only a virtue but a necessity. You would think the plan's architects -- the president and the Republican congressional leaders -- would have known this. These are the same guys, after all, who insist they want to simplify the tax code. These are the guys who rail against the blizzard of paperwork with which government afflicts us.

Indeed, if you can remember back to the winter of 1993-94, when Bill Clinton unveiled his never-to-be-enacted plan for universal health coverage, you may recall how Bob Dole, then the Republican Senate leader, helped bring it down. After Clinton laid out his proposal, Dole, in his rebuttal, produced an incomprehensible diagram that he said depicted Clinton's incomprehensible plan.

Clinton's plan was damn near incomprehensible. But it was simplicity itself compared with the maze that is Medicare Part D.

There is, however, one particularly helpful guide to all the options: Medicare's Plan Finder, which simplifies comparison shopping on the Medicare Web site. There's just one problem: Most American seniors don't go online. While surveys show that roughly 70 percent of Americans have ventured online, only 23 to 30 percent of seniors have ever done so.

But the seniors don't seem to have been uppermost in the minds of Part D's devisers. The foremost objects of their solicitude were the drug companies, which forked over roughly $30 million in the elections of 2002 (Part D was enacted in 2003), three-quarters of that to Republicans. Not surprisingly, Part D forbids the government from negotiating with drug companies to bring down the price of medications. The Republican leaders also looked out for the private insurance companies, to whose mercies the act entrusted America's elderly. That was a departure, of course, from traditional Medicare, which is one big, simple, popular and successful government single-payer plan on which our seniors gladly rely.

But structuring the drug benefit as a government program (much less a government program that could eat into drug company profits) was never an option for President Bush or Tom DeLay. If that meant that seniors would confront a bewildering array of choices, needlessly high drug prices and a gaping hole in their coverage, well, who would be more resigned to the genius of the American system than seniors?

The paradox here is that this most capitalist of models is also the least efficient. With all our insurance companies competing to cover healthy Americans and shun the sick, and all our drug companies fighting to keep their prices free from negotiation with a mass purchaser, we end up spending close to 15 percent of our gross domestic product on medical care -- far more than any of the nations where the government itself covers health care out of its general revenue. Simplicity in a health care system is not just more intelligible; it's also cheaper. And with those employers who offer decent health care benefits at an increasing competitive disadvantage with the growing number of employers who don't, the logic of and need for a single-payer system steadily grows. Not that logic and need, in the calculus of the men who make our laws, amount to a hill of beans.

meyersonh@washpost.com