The Senate is expected to vote Nov. 21 on whether to take up health legislation that would cover five million fewer people than a companion bill passed by the House, but would cost less. A major difference between the bills is the effective date for important provisions, like the requirement for people to obtain insurance and the obligation of employers to help pay for it. Many provisions of the House bill would take effect in 2013. But to help hold down the cost of the bill, Senate Majority Leader Harry Reid decided to delay the effective date for many provisions by one year, to 2014.