The Calamus Foundation is a left-of-center grantmaking foundation that provides financial support to LGBT advocacy groups and organizations that assist HIV/AIDS patients. To a lesser extent, it also funds architectural education.  It distributes over $1 million annually to these causes, particularly to those that aid the elderly LGBT community.
The Calamus Foundation was founded in 1994 by architect Saul “Shelly” Kaplan, a regular donor to the LGBT-interest litigation organization Lambda Legal and co-founder of its Liberty Circle, a group made up of the organization’s highest-contributing supporters.  He passed away in 2004, donating $20 million from his estate to the Foundation. 
In 2006, The Calamus Foundation’s current Executive Director, Brian O’Donnell, assumed his position, which he continues to hold as of August 2019. 
In 2015, Calamus made its largest donation to date: a $1 million grant to Services and Advocacy for Gay Lesbian Bisexual and Transgender Elders (SAGE) to fund its “LGBT Elder Housing Initiative.” 
Present Funding Activities
The Calamus Foundation does not accept unsolicited proposals for funding. It often donates to the same charities year after year, with the bulk of its grants going to the American Civil Liberties Union, the NY LGBT Center, the Transgender Legal Defense and Education Fund, and SAGE. 
Its largest donations go to SAGE, in the form of a recurring $350,000 yearly grant.
The Calamus Foundation’s Executive Director is Brian O’Donnell, who draws a yearly salary of $72,000. O’Donnell is also the manager of the National Grants Program at Broadway Cares/Equity Fights AIDS, which donated $13,691,316 to AIDS and arts-related causes in 2018.  Outside of nonprofit work, O’Donnell is a director, his most recent project being the 2015 gay “coming-of-age” film, AKRON.
Louis Bradbury, one of the Calamus Foundation’s four directors, was the longtime Chairman of New York’s Empire State Pride Agenda, what was formerly the largest New York State-specific LGBT-interest lobbying group.  It played a key role in some of the state’s most prominent pro-LGBT laws, including the Sexual Orientation Non-Discrimination Act, the Dignity for All Students Act, and state recognition of same-sex marriages. 
The Calamus Foundation’s most recent publicly available filings show total revenues of $372,015 and total expenses of $1,772,444.  Its revenues come entirely from its investments, which were made through the $20 million that was bestowed to it by its late founder, Saul Kaplan.