No. The value of employer-paid health insurance for an employee, spouse, and dependent is a tax-free fringe benefit. However, under the Affordable Care Act, employers (other than small employers currently exempt from this obligation) must report health insurance on W-2s. Presumably, this information is being used by the government for rules in the future; there is no current or future rule on the books that taxes this fringe benefit.
Generally, the receipt of cash or its equivalent accompanying an exchange of property. In a tax-free exchange, boot is subject to immediate tax.