The Obama administration “misled” Americans into thinking signing up for Obamacare would be cheaper than it really was, according to an inspector general’s report Thursday that said the IRS dramatically understated the actual cost of enrolling. IRS officials sent the letters to try to prod Americans to comply with the 2010 health law’s “individual mandate” that penalizes them for not holding coverage. But as part of the letters, the IRS said most people could find plans for $75 a month or less once government subsidies were figured in. That was untrue — in fact, the average cost was more than twice that figure, at $168 a month, the Treasury Inspector General for Tax Administration said. “Many of the nearly 7.5 million taxpayers who receive letters and seek insurance may feel misled if the actual cost of their insurance is much higher than the $75 per month detailed in their notification letter,” the inspector general concluded. The IRS said it was only using numbers provided by Department of Health and Human Services and verified by the Treasury Department. They said the $75 figure was true for some taxpayers. The inspector general said it asked for that documentation but never received it. Auditors said their own analysis found the HHS studies were based on a smaller sample and was limited to those who chose lower-coverage plans with fewer benefits. According to the new audit, federal regulations require agencies to present accurate information.