LGBT vs LGBTQIA+

LGBT and LGBTQIA+ both are nouns.

Word	Noun	Adjective	Verb	Adverb
LGBT	Yes	No	No	No
LGBTQIA+	Yes	No	No	No

As nouns, LGBT and LGBTQIA+ are synonyms defined as:

LGBT and LGBTQIA+: the community of people who have a non-normative gender and/or sexual identity, including lesbian, gay, bisexual, transgender, intersex, or asexual

Other synonyms of LGBT include LGBT+, LGBTQ, LGBTQIA.

LGBT (noun)	LGBTQIA+ (noun)
the community of people who have a non-normative gender and/or sexual identity, including lesbian, gay, bisexual, transgender, intersex, or asexual	the community of people who have a non-normative gender and/or sexual identity, including lesbian, gay, bisexual, transgender, intersex, or asexual