The PRC long ago declared the nation comprises exactly 56 nationalities (民族), including the Han. In fact, some ethnic groups were lumped together with others whose languages and cultures are arguably quite different, but the government strongly resists creating any new “nationalities.”
Interestingly, Taiwan has belatedly begun to investigate such claims on the island and, in some cases, granted belated recognition. The Sakizaya (撒奇萊雅族) of northern Taiwan (Keelung, Taipei, Taoyuan and Hwalien), an Austronesian people, were formerly considered Amis, a tribe that speaks a language whose grammar is in fact quite dissimilar. Since 2007, the Sakizaya are now recognized as one of Taiwan’s 14 aboriginal tribes.
Taiwan Today reports that a Sakizaya writer has won an award for his work in documenting the struggle for recognition of his people:
[Taiwan] Elementary school teacher Lisin Codat took away the  prize for aboriginal reportage. A Sakizaya, Lisin Codat interviewed his father-in-law and aunt and documented the efforts of these two leading figures in seeking official government recognition for their indigenous group, formerly lumped under the Amis.