Wiki:
LGBT is an initialism that stands for lesbian, gay, bisexual, and transgender. In use since the 1990s, the term is an adaptation of the initialism LGB, which itself started replacing "gay" when in reference to the community beginning in the mid-to-late 1980s, as many felt the term "gay community" did not accurately represent all those to whom it referred. The initialism has become mainstream as a self-designation and has been adopted by the majority of sexuality and gender identity-based community centers and media in the United States and some other English-speaking countries.
The term LGBT is intended to emphasize a diversity of sexuality and gender identity-based cultures and is sometimes used to refer to anyone who is non-heterosexual or non-cisgender instead of exclusively to people who are lesbian, gay, bisexual, or transgender. To recognize this inclusion, a popular variant adds the letter Q for those who identify as queer and/or are questioning their sexual identity as LGBTQ, recorded since 1996.
On the one hand, some intersex people who want to be included in LGBT groups suggest an extended initialism LGBTI (recorded since 1999. This initialism "LGBTI" is used in all parts of "The Activist's Guide" of the Yogyakarta Principles in Action. Furthermore, the initialism LGBTIH has seen use in India to encompass the hijra third gender identity and the related subculture. More recently the catch-all term "Gender and Sexual Diversity" GSD has been proposed.
I trust that settles the matter.