The taxing power is a well-established basis for enacting an individual mandate. Indeed, this country has had a tax-based mandate to purchase health care insurance for nearly 45 years. The Medicare program imposes a payroll tax on Americans as a way to fund coverage of their hospital costs once they reach age 65. People cannot opt out of Medicare; it is an obligatory system of health care insurance for one's senior years. Similarly, Congress can use a payroll tax to implement a mandate for individuals to purchase health insurance before they reach age 65. Under the House bill, for example, people will pay a 2.5 percent tax on their income unless they have health care coverage.
Under the commerce clause, Congress has the power to regulate interstate commerce, and the health care insurance industry clearly falls within the Supreme Court's understanding of interstate commerce.
[Image via drboyceretirement.blogspot.com/ ]