She specializes in administrative and regulatory law, including public procurement and bidding processes, administrative proceedings, administrative litigation, claims against the State, defense in sanctioning proceedings, regulatory advisory work, and consumer protection.

María Morena del Río has been actively involved in infrastructure and public works matters across a wide range of industries, including transportation, water and sanitation, telecommunications, broadcasting, postal services, energy, hydrocarbons, and general industry. She has also worked extensively on matters related to pharmaceuticals and medical devices, as well as healthcare contracts, regulations, and service delivery.

In the environmental field, her practice focuses on providing comprehensive advice on industrial siting, facility expansions, business reconversion processes, permit and authorization procedures, and both individual and collective environmental litigation.

She has been recognized as a leading practitioner in Administrative and Environmental Law by internationally renowned publications such as Chambers & Partners Latin America, The Legal 500 Latin America, Latin Lawyer 250, and The Best Lawyers in Argentina.

She is Director of the Administrative Law course at the University of Palermo, is Head Teaching Assistant for the same subject at the University of Buenos Aires School of Law, and teaches postgraduate courses at the Catholic University of Argentina and the University of San Andrés. She has published academic articles and lectured extensively on topics within her area of expertise.

She was a partner at Allende & Brea (2003–2025), where she led the Administrative Law department and co-headed the Life Sciences and ESG departments. She previously worked in the administrative law practice at M&M Bomchil under Dr. Guido S. Tawil (1998–2003) and practiced law in the province of Neuquén (1996–1998).