Dr. Trejo was appointed as Executive Director for Aging and Community Services, a branch of the Los Angeles County Department of Workforce Development, Aging and Community Services (WDACS) in 2021. In this capacity, she leads efforts to create a new department to proactively establish a coordinated strategy and service delivery system for older adults and adults with disabilities, while overseeing programs and operations, including Adult Protective Services, the Area Agency on Aging, and community service centers.  

Dr. Trejo has over 36 years of experience serving the residents of the Los Angeles region, including as General Manager of the City of Los Angeles Department of Aging and as the first District Chief for countywide older adult mental health for the Los Angeles County Department of Mental Health. Since 2016, Dr. Trejo has been leading Purposeful Aging L.A. an age-friendly initiative “to make the Los Angeles region the most age friendly in the world.” Among her other activities, she is co-lead for the Los Angeles Aging Disability Resource Connection (ADRC) and serves as a founding Co-Director/Investigator of the UCLA Los Angeles Community Academic Partnership for Research in Aging (LA CAPRA). 

Nationally, Dr. Trejo is active in the American Society on Aging, where she served as founding chair of the Mental Health and Aging Network and is currently on the Generations Journal Editorial Advisory Board; a member of the USAging National Aging and Disability Transportation Center (NADTC)’s National Advisory Committee on Transportation Diversity, Equity, and Inclusion; and on the board of directors of the Alzheimer’s Association, National Hispanic Council on Aging, and National Council on Aging; and founding member of the federal Advisory Council on Alzheimer's Research, Care, and Services. She currently serves as vice-president of the California Association of Area Agencies on Aging.

Dr. Trejo holds a doctorate in Social Work, Master level degrees in Gerontology and Public Administration, and a Graduate Certificate in Long Term-Care Administration all from the University of Southern California.  She has consulted and trained extensively throughout the U.S. on the development of programs for older adults with an emphasis on cultural competence. She has worked with individual countries and international organizations to develop initiatives and programs in the areas of aging, mental health, health, Alzheimer’s, and rehabilitation. Her work has been published in professional journals, book chapters, and major reports.

Dr. Trejo’s commitment to excellence have earned recognition in program innovation and as an influential leader, among the most noteworthy are the Robert Wood Johnson Foundation’s Community Health Leadership award, considered the nation’s highest honor in community health, and Excellence in Leadership awards from the National Association of Area Agencies on Aging (now USAging), American Society on Aging, and National Hispanic Council on Aging. Dr. Trejo’s efforts as an advocate elevating the needs of those most in need have been recognized by Justice in Aging, Los Angeles Aging Advocacy Coalition, Mexican American Opportunities Foundation, Fearless Caregiver.com, and the City of Hope. Los Angeles Magazine named her among the “50 Most Influential Women” and the United States Library of Congress has recognized Dr. Trejo’s accomplishments as a force for social change.