The rate of gun deaths in the United States rose to about 12 per 100,000 people, the second consecutive increase after a period of relative stability.

The rate of gun deaths in the United States rose in 2016 to about 12 per 100,000 people, the Centers for Disease Control and Prevention said in a report released on Friday. That was up from a rate of about 11 for every 100,000 people in 2015, and it reflected the second consecutive year that the mortality rate in that category rose in the United States.

The report, compiled by the C.D.C.’s National Center for Health Statistics, showed preliminary data that came after several years in which the rate was relatively flat.

“The fact that we are seeing increases in the firearm-related deaths after a long period where it has been stable is concerning,” Bob Anderson, chief of the mortality statistics branch at the health statistics center, said in a telephone interview on Friday. “It is a pretty sharp increase for one year.”

Mr. Anderson also said the rates for the first quarter of this year showed an upward trend, compared with the same three-month period of 2016.

“It clearly shows an increase,” he said, while emphasizing the data was preliminary. “With firearm-related deaths it is seasonal — the rates generally are a little higher in the middle of the year than they are at the end of the year,” he added. “Homicides are more common in the summer.”

More than 33,000 people die in firearm-related deaths in the United States every year, according to an annual average compiled from C.D.C. data.

The data released on Friday did single out other causes of death in the United States that were higher than the firearm-related rate. The drug overdose rate, for example, was almost 20 deaths per 100,000 last year, up from 16.3 in 2015.

The death rate for diabetes was about 25 per 100,000 people; cancer was 185 per l00,000, and heart disease about 196 deaths per 100,000 people.

But statistics about gun deaths, nearly two-thirds of which are suicides, have been ingrained in the national discourse in the United States, particularly after mass shootings, such as the one in Las Vegas last month in which 58 people were killed, and in debates over legislation related to guns.

In June 2016, the 49 fatalities in the Pulse nightclub shooting in Orlando represented one of the highest death tolls in a single mass shooting in recent United States history. But gun violence researchers note that although mass shooting fatalities account for no more than 2 percent of total deaths from firearm violence, they are having an outsize effect.

Garen J. Wintemute, director of the Violence Prevention Research Program at the University of California, Davis, School of Medicine, wrote in the Annals of Internal Medicine after the Las Vegas shooting that mass killings are “reshaping the character of American public life.”

“Whoever we are, they happen to people just like us; they happen in places just like our places,” he wrote. “We all sense that we are at risk.”

Dr. Wintemute said the latest C.D.C. report means the nation is approaching two decades since there has been any substantial improvement in the rate of gun deaths. The rate for the first three months of 2017 was about the same as the corresponding period in 2016. Hopefully, that is a sign it will level off again, Dr. Wintemute told The Associated Press.

Mr. Anderson said the data was not broken down by states, which each have different levels of comprehensiveness in their reporting to the federal agency. “As they get more and more timely we hope to include state-level information in these reports,” he said.

Suicides account for about 60 percent of firearm-related deaths, and homicides about 36 percent, Mr. Anderson said. Unintentional firearm deaths and those related to law enforcement officials account for about 1.3 percent each. The rest are undetermined.

The final data for 2016 will be released in the first week of December, Mr. Anderson said. “It could be this is a sort of blip, where it will stabilize again,” he said. “It is hard to predict.”