During 1999–2010, a total of 5,149 deaths from unintentional carbon monoxide poisoning occurred in the United States, an average of 430 deaths per year. The average annual death rate from carbon monoxide poisoning for males was more than three times higher than that for females. The death rates were highest among those 65 or older for males (0.42) and females (0.18). The rates were the lowest for males and females under 25.