According to the third quarter Nielsen survey (http://www.nielsen.com) of the smartphone market, 43% of Americans now own smartphones, up five percentage points in the past six months.

Android has 43% of the smartphone market and the iPhone has 28%, according to the research group. The phones held those exact percentages in Nielsen’s last survey three months ago.

Nielsen says that while 43% of all US mobile phone subscribers own a smartphone, described as “a mobile phone with a powerful operating system,” the vast majority of those under the age of 44 now have smartphones. In fact, 62% of mobile adults aged 25-34 report owning smartphones. And among those 18-24 and 35-44 years old the smartphone penetration rate is hovering near 54%.

Other groups show slightly lower penetration rates. Around 40% of 12-17 year-old teens and 40% of 45-54 year-olds reported owning a smartphone, as opposed to a more basic feature phone.

After younger adults, the segment with the second fastest-growing smartphone penetration rate is those aged 55-64. Smartphone penetration among this older group is only 30%, but it jumped five percent this quarter.