With Abbreviations
For group authors with abbreviations, use the full name and the abbreviation in the first citation. Then, use only the abbreviation in subsequent citations.
According to the National Institute of Mental Health (NIMH, 2019), women between the ages of 40 and 59 have the highest rates of depression in the United States.
Women between the ages of 40 and 50 have the highest rates of depression in the United States (National Institute of Mental Health [NIMH], 2019).
Without Abbreviations
For group authors without abbreviations, simply list the group author with the usual citation format.
According to Stanford University (2018), first-generation college students face many obstacles as they work to complete their degrees.
First-generation college students face many obstacles as they work to complete their degrees (Stanford University, 2018).