He previously served as high-profile mayor of the city and beach resort of Mar del Plata[1] in Buenos Aires Province.
Katz trained as an architect at the Universidad Nacional de Mar del Plata, where he later served as the Secretary General.
He was elected Mayor of Mar del Plata (and the surrounding General Pueyrredón Partido) in 2003.
Katz was a senior member of the Radical Civic Union but became a leading supporter of Peronist President Néstor Kirchner.
In the 2007 elections, he was placed second on the list of Kirchner's Front for Victory slate of candidates for national deputies for the Province of Buenos Aires.