Margarita Mercado focuses her practice in the area of litigation and regulatory.

From 2013 to 2016, Margarita served as solicitor general for the Commonwealth of Puerto Rico, a role in which she litigated prominent cases before the Puerto Rico Supreme Court and the US Federal Court of Appeals for the First Circuit. Following her tenure as solicitor general, Margarita was a solo practitioner handling civil litigation before the Commonwealth courts, the US District Court for the District of Puerto Rico and the US Court of Appeals for the First Circuit, as well as administrative agencies.