Comscore’s latest three-month study of U.S. smartphone market shows Apple’s iPhone and iOS platform both growing their shares. 

From the end of November through the end of February, Apple upped its share among OEMs to 38.9 percent from 35 and iOS boosted its share among smartphone operating systems to 38.9 percent from 35.

Meanwhile the same study showed Google’s Android still dominating the U.S. smartphone platform market, but dipping a little to 51.7 percent from 53.7.

Although Samsung did boost its U.S. smartphone OEM market share to 21.3 percent from 20.3, the Korean handset giant ended Comscore’s previous three-month study (in January) at 21.4 percent. That could indicate a leveling off for Samsung in the U.S., though the company’s new flagship Galaxy S4 launches soon and could spark a new round of growth.

The study estimates the U.S. smartphone user base to be around 133.7 million people. More than 60 percent of those users are opting for Apple or Samsung smartphones and Comscore rounds out the top five with HTC (9.3 percent), Motorola (8.4 percent) and LG (6.8 percent). The study indicates that HTC, Motorola and LG all lost market share since November.

According to Comscore, Apple and Google’s dominance over smartphone platforms is even more impressive, with the two combining to control more than 90 percent of the U.S. market. Over the course of the study, BlackBerry continued to lose favor, dipping to 5.4 percent from 7.3. But Microsoft’s Windows Phone did manage to boost its share to 3.2 percent from 3 percent.

BlackBerry just recently launched its new touchscreen flagship, the Z10, which carries the totally revamped BlackBerry 10 OS. Both Samsung and HTC have new flagship phones out in the coming weeks and Apple is widely rumored to be releasing a new iPhone (or multiple iPhones) as early as this summer.