Ocaña earned renown for her work in the Money Laundering and Capital flight Subcommittee in Congress, where in 2001 she led investigations into businessman Emir Yoma and Córdoba Province Vice Governor Germán Kammerath, among others.

President Fernando de la Rúa's resignation in December and the attendant crisis dissolved the Alliance, whereby Ocaña joined fellow Congresswoman Elisa Carrió's ARI, a new center-left christian democratic party.

Enjoying Carrió's esteem, she was invited to run on the ARI ticket for Governor of Buenos Aires Province, but declined, opting to stand for reelection as Congresswoman.

[3] Hoping to win a fraction of ARI voters over following their defeat in the October 2007 elections, President-elect Cristina Kirchner offered Ocaña the post of Health and Environment Minister, which the popular PAMI director accepted, taking office on December 10.

[4] Her departure from the Health Ministry was not announced until after the mid-term elections on June 28, and Tucumán Province surgeon and Vice Governor Juan Luis Manzur was tapped to succeed her on July 1.