(NBC News) - Hospitals are making fewer mistakes, from giving patients the wrong medications to giving them infections, according to a government report issued Tuesday.

As a result, 50,000 people are alive today who otherwise would have died, the Health and Human Services Department says in its report.

It's not clear why rates are down, but hospitals and HHS have made a concerted effort to try to stop the enormous rate of mistakes, which kill as many as 180,000 people a year, according to government estimates.

"Approximately 1.3 million fewer incidents of harm occurred in 2011, 2012, and 2013."

"Preliminary estimates for 2013 show that the national hospital-acquired condition rate declined by 9 percent from 2012 to 2013 and was 17 percent lower in 2013 than in 2010," the Center for Medicare and Medicaid Services, part of HHS, said in a statement.

"We estimate that approximately 800,000 fewer incidents of harm occurred in 2013 than would have occurred if the rate of hospital-acquired conditions had remained steady at the 2010 level. Cumulatively, approximately 1.3 million fewer incidents of harm occurred in 2011, 2012, and 2013 (compared to 2010)."

The biggest reduction was in adverse drug events — mistakes that include medication overdoses and giving the wrong drug, or a drug that a patient is allergic to. About 40 percent of the reduction was seen there. Twenty percent of the improvement was in bedsores, and another 14 percent from infections that patients get from catheters.

About 50,000 lives were saved in 2011, 2012 and 2013 combined because of the improvements — 35,000 in 2013 alone, CMS says.

The cost savings — $8 billion in 2013.

"A 17 percent reduction in hospital-acquired conditions is a big deal, but it's only a start," HHS Secretary Sylvia Burwell said at a conference in Baltimore Tuesday morning. "No American should ever lose his or her life, or spend the holidays in the hospital because of a condition that could have been prevented."

CMS looked at between 18,000 and 33,000 medical records for each year, looking for reports about mistakes such as infections, drug errors and pressure ulcers.

"There is still much more work to be done."

The findings build on a report issued by the Centers for Disease Control and Prevention in March that found some infections fell between 2008 and 2012. The same report found that one in 25 U.S. hospital patients has caught an infection while in the hospital — which adds up to 700,000 infections in 2011 alone.

"There is still much more work to be done," CMS said in Tuesday's report.

"The 2013 hospital-acquired condition rate of 121 hospital-acquired conditions per 1,000 discharges means that almost 10 percent of hospitalized patients experienced one or more of the hospital-acquired conditions we measured. That rate is still too high."

Federal officials and hospitals started looking at hospital errors in 1998, when the Institute of Medicine released a report showing that as many as 98,000 people a year died from medical errors.

In 2010, HHS reported that rates of bloodstream infections following surgery were increasing by 8 percent annually and medical errors in the hospital contributed to the deaths of as many as 180,000 Medicare patients each year.