Sebelius, Pelosi celebrate anniversary of ObamaCare court decision

"We recognize this is a huge undertaking. If it was easy, it would have been done decades ago, but we are on track, finally, to get it done. And I want to be clear: We are ready to go on October 1" when enrollment begins, she added.

This week marks one year since the Supreme Court upheld the vast majority of President Obama's signature legislative achievement.

In a 5-4 decision, with Chief Justice John Roberts writing the majority opinion, the court said the law's individual mandate to buy health insurance is constitutional as a tax.

The move dealt a major blow to conservative opponents of ObamaCare, who argued that the government cannot force citizens to purchase health coverage.

On Wednesday, Pelosi compared the Affordable Care Act to Social Security and Medicare as a "pillar of our society."

"Health independence — that's the third pillar — [is] something we're very, very proud to be about," said the California Democrat.

The event also marked less than 100 days until the new insurance exchanges open for enrollment.

HHS faces an intense summer as it finalizes more than 30 marketplaces and launches public education campaign about their benefits