Whitney Houston In Out-Patient Rehab Program

5/9/2011 8:20 AM PDT
Whitney Houston has checked herself in to an out-patient rehabilitation program ... TMZ has learned.

A source directly connected with Whitney tells us ... Houston enrolled in the program around 10 days ago.  The program allows Houston to go out in public ... as long as she has a monitor.

Just last weekend, Houston was enjoying herself at a Prince concert in L.A. ... with her daughter right by her side.

Our source is not saying why Houston is seeking treatment ... but we're told, "She's cleansing herself to get ready for a new movie."