The Intersex movement in the US is small, overlooked, and stigmatized, much as the Transgender movement once was before it was included in the larger LGB movement.
But already, more and more groups are changing LGBT to LGBTI to recognize and advocate for the Interesex community.
The Transgender movement was included in the early 2000s despite the fact that Transgender individuals didn't always have much in common with lesbians, gays, and bisexuals. History proved, however, that they are more alike than different and they are stronger TOGETHER!
That is why the Intersex community, although in many ways different than LGB or Trans people, should be a part of the inclusive LGBT movement! Although not all Intersex people deal with the same issues of gender-identity and homosexuality, many do. And, even bigger still, the Intersex movement is still fighting to stop infant "corrective" genital surgeries that are performed unnecessarily every day!
The Intersex movement seeks the same things that most civil rights struggles seek: mainstream acceptance, equality under the law, and the right to be safely "out."
Turning the LGBT movement into the LGBTI movement would benefit both sides and promote awareness and advocacy for Intersex people! It would break down the stigma surrounding Intersex people while, at the same time, help break down the destructive gender binary that is restricting our society and deterring love and acceptance of sex and gender ambiguous individuals!
A few organizations that already include LGBTI:
ILGA Internationa Lesbian, Gay, Bisexual, Trans, and Intersex Association
LGBTI Community Legal Services
LGBTI National Health Alliance, Australia
and many more!