Medium Season 6 Episode 22 (Medium s06e22) with title “It’s a Wonderful Death” airs on Friday, May 21st 2010 at 09:00 pm via CBS.
Here is summary for Medium Season 6 Episode 22 :

When Allison’s brain tumor resurfaces, its aftermath could have life-altering consequences for her friends and family.

Few hours after original series aired on TV, online streaming video for Medium Season 6 Episode 22 usually available on Net and of course, if video available, as soon as possible will show you where you can watch this episode for free.