The medical device tax was designed to raise money to help fund the Patient Protection and Affordable Care Act. Increasingly, it appears the tax will raise more hackles than dollars.

The Congressional Research Service conducted the latest study of the projected effects of the tax, a 2.3 percent excise charge on sales of certain medical devices. In short, it found that the tax would have a negligible negative impact on the medical device industry, but that it also wouldn't produce much revenue because of the many limitations built into it.

"Opponents of the tax claim that the medical device tax could have significant, negative consequences for the U.S. medical device industry and on jobs. The estimates in this report suggest fairly minor effects, with output and employment in the industry falling by no more than two-tenths of 1 percent. This limited effect is due to the small tax rate, the exemption of approximately half of output, and the relatively insensitive demand for health services," says the CRS in its summary of the tax.