What's the difference between the K50 and K55 Keurig coffee maker? And, can you use other pods in this coffee maker that aren't K-cups?

Hello shortcake and thank you for your question. The K55 and the K50 brewing system are the same brewer, they are simply packaged differently based off of the retailer that provides them. We recommend you only use products with the “Keurig Brewed” seal with the Keurig Brewer as these meet the Keurig standards for taste, quality and safety and are tested to perform in the Keurig Brewer. We hope this information is helpful!