Economists agree on theoretical grounds and have shown empirically that all contributions toward premiums—those made by employers and workers alike—are forgone wages. In other words, wages are lower by exactly the amount of the premium, even when the employer seems to pay it. What’s going on here is that employers are shifting compensation from wages to premiums. The preferential tax treatment of the latter encourages this.
Because wages are taxed, compensation in the form of health insurance in lieu of wages reduces government revenue. In fact, it reduces it a lot: $250 billion per year. Just to put that figure in perspective, $250 billion is almost half the Medicare budget. It is more than 3½ times the average annual cost of the Affordable Care Act’s low-income health insurance subsidies. Employer-sponsored health insurance is among the most subsidized types of health insurance in America, almost as subsidized as Medicaid.
The preferential tax treatment of employer-sponsored health insurance also encourages more generous coverage and higher health care spending. By one estimate, health spending among insured workers is 26% higher than it otherwise would be if not for the tax break.
We should get rid of the employer healthcare tax subsidy. It distorts purchasing incentives, it's a massive middle class welfare program, and it drives up the cost of healthcare. It's toxic and it needs to go. (McCain's healthcare plan would have accomplished that. The Obama campaign blatantly lied about it for 6 months and we got Obamacare instead. I'm still angry about that.)