According to Variety, Ricky and Morty's imminent return was announced at the WarnerMedia upfront presentation in NY.
The news was announced this morning by WarnerMedia during a presentation in NY (via Variety), though at this time there's no precise day of release. That'll put the show over the halfway point for the total of 70 episodes (so far) ordered by Adult Swim, so there's plenty more sci-fi hijinks in store for the future of Dan Harmon and Justin Roiland's phenomenon.
It was announced last May that Adult Swim had given "Rick and Morty" a massive 70-episode order, which will bring the series to 101 episodes. We want the episodes to stay good, but we do also want to try to turn them around a little quicker now that we have this big order, I think it gives us the ability to be faster. And you need to get used to waiting through long breaks between seasons. The end of the third season ended with a bit of a reset, going back to the formula of the first season after the characters learned a lot of about themselves. "It's going to be really cool".
Season 4 will premiere just over two years after the finale of Season 3 in October 2017, the longest gap yet between seasons of the show. This season the rest of the family, his son-in-law Jerry (Chris Parnell), grand-daughter Summer (Spencer Grammer) and grandson Morty (Justin Roiland) are dragged into Rick's intergalactic adventures, as he faces new threats and mysteries of his secret past are revealed. "Brand new Season 4 in November 2019, this year".