I thought the immediate family of a former prez is entitled to USSS protection for a couple years, and the prez gets it for life. But I could be wrong.
[Does anyone remember the story here? When the Clintons were in Washington D.C. driving past the White House during the late 80's, Chelsea asked her mom if they could stop for a visit and was told "Not until decent people are living there." It all depends on what the definition of 'decent' is, one supposes.]