Want to know one of the most common Keurig-related questions we're asked?
What's the difference between Keurig's B series and K series brewers?
Answer: Nothing. The switch from B to K was solely a marketing decision as the company realized branding their brewers with a K made more sense. (They're called Keurig, after all.)
The B40 is part of Keurig's flagship B40 series. Currently discontinued, it was replaced by the K40 series.
In turn, the K40 series was rebranded as the K50 series, and eventually the B40s, K40s, and K50s were all discontinued and replaced by the K-Classic, which offers many of the features you'll find on B40/K40/K50 brewers:
There are just two major differences between the B40/K40/K50 brewers and the K-Classic: