Just yesterday we heard rumors that a 4.4.3 version of Android might be coming soon to the Nexus 5 smartphone. It turns out that rumor was true, at least for Sprint customers. Sprint rolled out an update on their software support pages detailing the new version of Android for the Nexus 5.
As you can see in the pic above, this update is primarily just a number of Android bug fixes, although it also enables Sprint Spark band 26 and band 41. It's important to note that Google is testing this update for release for all Nexus 5 smartphones (and later for other Android devices). We will keep you apprised when the update hits anything else.
Source: Sprint