“Sicko” is a documentary, but it’s a comedy, too — and a family drama and a travelogue and, ultimately, a horror movie.

It’s also the rare Michael Moore film that isn’t primarily about Michael Moore — at least not for the first hour or so. He truly seems to be aiming for the greater good here, not just pushing a personal agenda or carrying out a vendetta as he appeared to do in “Roger & Me” and “Fahrenheit 9/11.”

But it is quintessential Moore: expertly crafted, eminently entertaining, one-sided and overly simplistic.

And incredibly persuasive. In exposing the ills of America’s health care system, the pot-stirring documentarian introduces us to regular folks — with and without health insurance — and lets them tell their stories of frustration, pain and loss. In doing so, he puts a human face on an enormously daunting topic, one that sounds inherently dry and non-visual.

One man sits in his living room, stitching up the knee he sliced open in an accident, while his cat looks languidly on. Another recounts how he severed the tips of two fingers with a saw, and had to choose between reattaching one for $60,000 or the other for a mere $12,000.

These are the absurdly funny anecdotes. On the opposite end of the spectrum, a mother tearfully recalls losing her 18-month-old daughter, who was refused treatment for a 104-degree fever because the hospital they visited wasn’t part of the Kaiser Permanente system. Another woman, who happened to work at a hospital, discusses how her husband died because he was denied a bone-marrow transplant.

In the middle are enlightening tales from current and former insurance company employees, including a young woman who works at call center taking applications. Unexpectedly, she chokes up at the memory of providing false hope to a couple she knew would be denied coverage, and explains that that’s why she’s so abrupt on the phone now — she doesn’t want to get to know these people and their problems, she doesn’t want to become emotionally attached.

As in “Bowling for Columbine,” it’s in these instances that Moore, the self-professed man of the people, is at his strongest. People want to share their stories — they want to vent and connect and feel that they’re not alone. Moore allows them to do that simply and powerfully.

Of course, he’s also a master showman with a subversive sense of humor and a need to needle. So he has a little fun with his old buddy, President Bush. As always, he blankets the film in voiceover that ranges from bemused to mocking to self-righteous. And in his trademark fashion, he weaves in archival footage of idyllic, Eisenhower-era America, along with some propaganda films intended to inspire fear of socialism. The pacing is always speedy, the energy high.

Then, in the second half of “Sicko,” Moore visits Britain, France and — in a climactic bit of literal showboating — Cuba, all countries where citizens enjoy the benefits of government-run medical care. In his much-ballyhooed trip to Guantanamo Bay, he stands at the front of a boat, surrounded by some of the men and women who volunteered at ground zero after 9/11 and have suffered physical and mental health problems ever since, and asks through a bullhorn that they receive the same medical treatment as the prisoners there. Of course he knew from the moment he pulled away from the dock in Miami that they wouldn’t get the attention they sought, but still — it makes for good theater.

What weakens “Sicko” is that Moore never offers a single dissenting voice or even suggests in a cursory way that he tried to reach any political leaders or insurance executives for a response. We’re told that top administrators receive bonuses for denying care, for example — that the less coverage they provide, the fewer people they help, the more money they save their companies — but there’s no one to explain or defend this practice. Nor does Moore bother to mention how much it might cost to institute universal health care in the United States.

Instead he tickles the funny bone and tugs at the heart — with surgical precision. “Sicko,” a Lionsgate and Weinstein Co. release, is rated PG-13 for brief strong language. Running time: 123 minutes. Three stars out of four.

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Motion Picture Association of America rating definitions:

G — General audiences. All ages admitted.

PG — Parental guidance suggested. Some material may not be suitable for children.

PG-13 — Special parental guidance strongly suggested for children under 13. Some material may be inappropriate for young children.

R — Restricted. Under 17 requires accompanying parent or adult guardian.

NC-17 — No one under 17 admitted.