The Mars 2020 rover will land in February 2021. Like its predecessors Curiosity, Opportunity, and Spirit, it will need to return most of its data through orbital relays. So it's kind of a problem that there aren't currently any new NASA Mars orbiters planned. The most recently-arrived orbiter is MAVEN, and it's expected to do a great deal of data relay for Mars 2020. But its orbit can't produce the repetitive afternoon communication session that Mars orbiters have come to rely on. My colleagues Casey Dreier and Jason Callahan wrote an article about this problem last year.
The Opportunity and Curiosity rovers have been sending data to Earth via the Odyssey and Mars Reconnaissance Orbiters. Both of these workhorse spacecraft are far, far past their warrantied lives (as is Opportunity and the one other orbiter capable of data relay, ESA's Mars Express). Every new year, I predict that we'll finish out the year having seen at least one of these aging spacecraft go silent, and every new year's eve I'm delighted to find out I've been wrong. Through the tender care of their Earth-based engineering teams, these elderly spacecraft have kept going.