Yes, but only at 30Hz.
With OS X Yosemite v10.10.3, most single-stream 4K (3840x2160) displays are supported at 60Hz operation on the following Mac computers:
MacBook Pro (Retina, 13-inch, Early 2015)
MacBook Pro (Retina, 15-inch, Mid 2014)
Mac Pro (Late 2013)
iMac (27-inch, Late 2013 and later)
Mac mini (Late 2014)
MacBook Air (Early 2015)
MacBook (Retina, 12-inch, Early 2015)
yeah i believe higher resolution needs extra adapters, probably a display port adapter. the apple hdmi adapter seems to only support up to 1080p
the apple hdmi adapter seems to only support up to 1080p
A USB Type-C to DisplayPort cable like this one.