The CIF voted in April 2017 to revise its rules regarding "athletically motivated" transfers effective July 1, 2017. The bylaws previously prohibited "athletically motivated" transfers, as defined by the CIF, and if a transfer was found to be such, the student-athlete would lose a year of eligibility unless there was an applicable exception such as a valid change of residence or a qualifying hardship.
Now, students are allowed to transfer for athletically motivated reasons, such as a better sports program, more visibility, etc. Certain things are still forbidden however, such as following a coach to a new school or being recruited to a new school. And the Sit Out Periods still apply as they previously did.