http://www.defense.gov/news/newsarticle.aspx?id=44767
According to the link above, the military TSP didn't become available until 10/9/2001. This makes sense because I hired on in 2000 and I know it wasn't available to the military when I got hired. I remember it becoming available to them after I had already started my civil service career. I do also remember the S and I Funds coming not too long after I hired on, so 2001 does indeed sound accurate for those options as well.
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