Ranger School for SF Qualified

[Foggy Bottom]

How is it determined whether or not a current (or prospective) Special Forces qualified soldier attends Ranger school? I understand that many, for example officers coming from combat arms branches, will be Ranger qualified prior to even being considered for Special Forces; or soldiers coming out of Ranger Battalion. If someone's intent is to join Special Forces, how is a decision made to send someone to Ranger school?

My specific situation is that I intend on attending a combat arms branch BOLC in the near future through ARNG. From now until meeting the TIS/rank requirements to attend SFAS, should I actively be seeking a spot in Ranger school or would 19th/20th Group send me prior to SFAS/SFQC? Or do individuals typically self-select on whether or not they wish to attend for their own professional development?