LOS ANGELES, June 19 — Hyped in Cuba, unveiled in Cannes, pirated on YouTube, and rallied around last week in Sacramento, Calif., by nurses chanting for the health insurance system’s demise, Michael Moore’s documentary “Sicko” is finally ready to meet its American audience — or at least some of it — a week ahead of schedule.

Executives of the Weinstein Company, which provided backing for the film, a documentary indictment of America’s health care system, said “Sicko” would open Friday on a single screen at the AMC Loews Lincoln Square theater in New York.

Lionsgate, the movie’s distributor, will otherwise proceed with a planned opening in about 250 theaters around the country the following Friday. But it is offering “sneak previews” this week in 27 markets where Mr. Moore’s politically tinged documentaries have played well in the past, including San Francisco, Los Angeles, Boston, and Philadelphia, the Weinstein executives said.

“This gets it started,” said Gary Faber, Weinstein’s executive vice president in charge of marketing, who said the early opening was intended to feed growing demand for the film and was not related to the movie showing up on the Internet.