We have good news and bad news. The good news: No, coffee doesn’t really “go bad” in the way that bread grows mold or a banana slowly rots on your countertop. And drinking coffee made from old beans won’t make you sick, even if the expiration date has passed. (We can’t vouch for the taste, though.)
One small caveat: Dry coffee grounds and whole coffee beans won’t go bad or rot, but once you get those grounds wet, you can’t reuse them, and a pot of brewed coffee can go bad (read: grow mold) if you let it sit around long enough. The natural oils in coffee will go rancid over time, and no one wants rancid coffee…or week-old coffee, for that matter.