...behind the scenes, White House officials discussed whether that was a promise they could keep.

When the question arose, Mr. Obama's advisers decided that the assertion was fair, interviews with more than a dozen people involved in crafting and explaining the president's health-care plan show.

But at times, there was second-guessing. At one point, aides discussed whether Mr. Obama might use more in-depth discussions, such as media interviews, to explain the nuances of the succinct line in his stump speeches, a former aide said. Officials worried, though, that delving into details such as the small number of people who might lose insurance could be confusing and would clutter the president's message.

"You try to talk about health care in broad, intelligible points that cut through, and you inevitably lose some accuracy when you do that," the former official said.

The former official added that in the midst of a hard-fought political debate "if you like your plan, you can probably keep it" isn't a salable point.

One former senior administration official said that as the law was being crafted by the White House and lawmakers, some White House policy advisers objected to the breadth of Mr. Obama's "keep your plan" promise. They were overruled by political aides, the former official said. The White House said it was unaware of the objections.

Jon Favreau, who served as Mr. Obama's top speech writer, said that as they tried to promote the overhaul plan and explain it to the public, the aim was to make it as simple as possible "while still being true."

"Simplification and ease of explanation were a premium, and that was true throughout the process," he said.

Richard Kirsch, the former national campaign manager of Health Care for America Now, which pushed for the 2010 health law, said the words were reassuring-and true-for the vast majority of the people, and so his group never raised concerns about that claim. Adding an asterisk to note that people who had "shoddy insurance" might need to change plans was not practical, he said.

"The actual, accurate statement is if you have good insurance, and you like it, you can keep it," said Mr. Kirsch, now a senior fellow at the Roosevelt Institute, a liberal policy organization.