WASHINGTON — The health care bill headed for a vote in the House this week costs $1.2 trillion or more over a decade, according to numerous Democratic officials and figures contained in an analysis by congressional budget experts, far higher than the $900 billion cited by President Barack Obama as a price tag for his reform plan.

While the Congressional Budget Office has put the cost of expanding coverage in the legislation at roughly $1 trillion, Democrats added billions more on higher spending for public health, a reinsurance program to hold down retiree health costs, payments for preventive services and more.