In 1976, Rich began her partnership with Jamaican-born novelist and editor Michelle Cliff, which lasted until her death. In her controversial work Of Woman Born: Motherhood as Experience and Institution, published the same year, Rich acknowledged that, for her, lesbianism was a political as well as a personal issue, writing, "The suppressed lesbian I had been carrying in me since adolescence began to stretch her limbs." The pamphlet Twenty-One Love Poems (1977), which was incorporated into the following year's Dream of a Common Language (1978), marked the first direct treatment of lesbian desire and sexuality in her writing, themes which run throughout her work afterwards, especially in A Wild Patience Has Taken Me This Far (1981) and some of her late poems in The Fact of a Doorframe (2001). In her analytical work Adrienne Rich: the moment of change, Langdell suggests these works represent a central rite of passage for the poet, as she (Rich) crossed a threshold into a newly constellated life and a "new relationship with the universe". During this period, Rich also wrote a number of key socio-political essays, including "Compulsory Heterosexuality and Lesbian Existence", one of the first to address the theme of lesbian existence. In this essay, she asks "how and why women's choice of women as passionate comrades, life partners, co-workers, lovers, community, has been crushed, invalidated, forced into hiding". Some of the essays were republished in On Lies, Secrets and Silence: Selected Prose, 1966–1978 (1979). In integrating such pieces into her work, Rich claimed her sexuality and took a role in leadership for sexual equality.
From 1976 to 1979, Rich taught at City College as well as Rutgers University as an English Professor. In 1979, she received an honorary doctorate from Smith College and moved with Cliff to Montague, MA. Ultimately, they moved to Santa Cruz, where Rich continued her career as a professor, lecturer, poet, and essayist. Rich and Cliff took over editorship of the lesbian arts journal Sinister Wisdom (1981–1983). Rich taught and lectured at Scripps College, San Jose State University, and Stanford University during the 1980s and 1990s. From 1981 to 1987, Rich served as an A.D. White Professor-At-Large for Cornell University. Rich published several volumes in the next few years: Your Native Land, Your Life (1986), Blood, Bread, and Poetry (1986), and Time’s Power: Poems 1985–1988 (1989). She also was awarded the Ruth Paul Lilly Poetry Prize (1986), the Elmer Holmes Bobst Award in Arts and Letters from NYU, and the National Poetry Association Award for Distinguished Service to the Art of Poetry (1989).
Rich's work with the New Jewish Agenda led to the founding of Bridges: A Journal for Jewish Feminists and Our Friends in 1990, a journal of which Rich served as the editor. This work coincided explored the relationship between private and public histories, especially in the case of Jewish women's rights. Her next published piece, An Atlas of the Difficult World (1991), won both the Los Angeles Times Book Award in Poetry and the Lenore Marshall/Nation Award as well as the Poet's Prize in 1993 and Commonwealth Award in Literature in 1991. During the 1990s Rich became an active member of numerous advisory boards such as the Boston Woman’s Fund, National Writers Union and Sisterhood in Support of Sisters in South Africa. On the role of the poet, she wrote, "We may feel bitterly how little our poems can do in the face of seemingly out-of-control technological power and seemingly limitless corporate greed, yet it has always been true that poetry can break isolation, show us to ourselves when we are outlawed or made invisible, remind us of beauty where no beauty seems possible, remind us of kinship where all is represented as separation." In July 1994, Rich won the MacArthur Fellowship and Award, specifically the "Genius Grant" for her work as a poet and writer. Also in 1992, Rich became a grandmother to Julia Arden Conrad and Charles Reddington Conrad.
There's a place between two stands of trees where the grass grows uphill and the old revolutionary road breaks off into shadows near a meeting-house abandoned by the persecuted who disappeared into those shadows. I've walked there picking mushrooms at the edge of dread, but don't be fooled this isn't a Russian poem, this is not somewhere else but here, our country moving closer to its own truth and dread, its own ways of making people disappear.“ ” From "What kinds of times are these?"
In 1997, Rich declined the National Medal of Arts in protesting against the House of Representatives’ vote to end the National Endowment for the Arts as well as other policies of the Clinton Administration regarding the arts generally and literature in particular, stating that "I could not accept such an award from President Clinton or this White House because the very meaning of art, as I understand it, is incompatible with the cynical politics of this administration...[Art] means nothing if it simply decorates the dinner table of the power which holds it hostage". Her next few volumes were a mix of poetry and essays: Midnight Salvage: Poems 1995–1998 (1999), The Art of the Possible: Essays and Conversations (2001), and Fox: Poems 1998–2000 (2001).
In the early 2000s, Rich participated in anti-war activities, protesting against the threat of war in Iraq, both through readings of her poetry and other activities. In 2002, she was appointed a chancellor of the newly augmented board of the Academy of American Poets, along with Yusef Komunyakaa, Lucille Clifton, Jay Wright (who declined the honor, refusing to serve), Louise Gluck, Heather McHugh, Rosanna Warren, Charles Wright, Robert Creeley, and Michael Palmer. She was the winner of the 2003 Yale Bollingen Prize for American Poetry and applauded by the panel of judges for her "honesty at once ferocious, humane, her deep learning, and her continuous poetic exploration and awareness of multiple selves." In October 2006, Equality Forum honored Rich's work, featuring her as an icon of LGBT history.
Rich died on March 27, 2012, at the age of 82 in her Santa Cruz, California home. Her son, Pablo Conrad, reported that her death resulted from long-term rheumatoid arthritis. Her last collection was published the year before her death. Rich was survived by her sons, two grandchildren and her partner Michelle Cliff.