Google has started rolling out the July 2019 Android security patch for its Pixel line of smartphones.
The update is rolling out right now, but can take a couple of weeks to roll out to everyone. So, if you don’t like waiting, you can grab the factory images and OTA files to install, if you know how to follow that process.
Otherwise, you can check for the update manually by going into Settings > System > Advanced > System Update.
Oddly enough, we haven’t yet seen the patch appear for the Pixel C, which could indicate that Google might be dropping support.