Found this in my house in Colorado. I took this picture before releasing it. I didn't measure it, but the diameter of the cup it is trapped under is about 5.5 cm, so that makes it about 1.1 cm long. It easily climbed up the side of the glass cup.
This shield bug belongs to the species Perillus bioculatus, and has the nickname "two-spotted stink bug". They're native to the United States, and come in a variety of colors.
You mention that its colors are yellow & black, however, from the image you provide, it seems more of a pale yellow/off white. Because of that, I think it your found insect more closely resembles the first of the following images, whereas you may think it's closer to the second.
And then, a few other colors:
$\begingroup$ You meant "two-spotted stink bug" instead of "sting," right? $\endgroup$– userSep 9, 2017 at 14:07
$\begingroup$ @PaulParker Oh, hah! Yes, thanks. Edit has been made. :) $\endgroup$– user22020Sep 9, 2017 at 14:09