A federal rule requires all hospitals to post online a master list of prices for the services they provide so consumers can review them starting Jan. 1.

The health care industry nationally has a reputation for having little price transparency, which can make it difficult for consumers to price compare. But the hospital's master list prices, sometimes called a chargemaster, is also not a complete look, consumer advocates say.

That's because the final bill a patient receives is almost never the same as the sticker price for the services they received. Insurance companies negotiate discounts on the sticker prices. Co-pays, co-insurance, deductibles also add other layers of complexity that bring discounts or increased costs before a final charge is determined.

"The list prices are so high that the vast majority of hospitals don't even try to collect list prices from uninsured patients," said Benedic Ippolito, with the American Enterprise Institute, who has researched hospital list prices.