The state of RCS messaging in the United States is a little bleak at the moment. Sure, it's got a massive character limit that puts SMS to shame, more multimedia options than MMS, and read receipts, but availability is inconsistent and the resources it takes to set up servers are not small. Verizon had planned on bringing on its RCS profile by "early 2019," and, if you consider "before July 1" early enough for you, it has succeeded in delivering it to the Samsung Galaxy S9 and S9+.
A new support page on Verizon's website details all the feature the two phones now have access to through its RCS Universal Profile. Unfortunately, only postpaid subscribers can chat through RCS with other postpaid Verizon Galaxy S9 and S9+ users, meaning that a lot of conversations will be stuck on SMS and MMS. Customers must opt in by heading to the settings page in their messaging app and tap on "Chat Settings." If it generates a menu of options, they can opt into RCS.
Mind you, Verizon also has the Pixel 3 and 3 XL as RCS-capable phones, but those use Google's Jibe servers, not Verizon's. We don't have any idea of if and when Verizon will bridge out to other servers at this time. Still, one small step for a carrier is part of one giant leap for all of the telecommunications business.