Top Senate Democrats are close to finalizing their health bill and could unveil a measure that would include stiffer penalties on employers who fail to provide health coverage. Senate leaders plan to submit the bill to the Congressional Budget Office for a cost estimate as soon as October 26, and make the legislation public as soon as a day later, according to a person familiar with the negotiations. The bill is expected to expand health coverage to tens of millions of Americans by giving low- and middle-income Americans subsidies to offset the cost of insurance, and expanding the Medicaid federal-state insurance program to cover a broader swath of the poor.