A Politico article posted last July explains how this works:
The California bill wouldn’t immediately open the state’s exchange to undocumented immigrants, who are primarily Latino. Instead, it would direct California to seek permission from the federal Department of Health and Human Services through an Obamacare waiver program that allows states to shape their own health care reforms.
However, the administration hasn’t spelled out the guidelines for the “state innovation waivers” program, which doesn’t start until 2017, and it’s unclear whether the White House would rethink its Obamacare coverage ban for undocumented immigrants. An HHS spokesperson said the department hasn’t discussed the California proposal with state officials and declined to comment on the bill.
Note that the waiver program was already built into the law. The Republicans in Congress have believed from the beginning of ObamaCare that the Democrat’s plan was to cover illegal aliens.
Wikipedia reminds us of an event that underlined that point:
On September 9, 2009, Wilson shouted at President Barack Obama while Obama addressed a joint session of Congress to outline his proposal for reforming health care. During his address, Obama said: “There are also those who claim that our reform effort will insure illegal immigrants. This, too, is false – the reforms I’m proposing would not apply to those who are here illegally.” In a breach of decorum, Wilson pointed at Obama and shouted, “You lie!” twice. Wilson attracted national and international attention for the incident. He said afterwards that his outburst reflected his view that the bill would provide government-subsidized benefits to illegal immigrants.
Then-White House Chief of Staff Rahm Emanuel immediately approached senior Republican lawmakers and asked them to identify the heckler and urge him to apologize immediately. Members of Congress from both parties condemned the outburst. “Totally disrespectful”, said Senator John McCain (R-Arizona) of Wilson’s utterance. “No place for it in that setting or any other and he should apologize immediately.” Wilson said later in a statement:
This evening I let my emotions get the best of me when listening to the President’s remarks regarding the coverage of illegal immigrants in the health care bill. While I disagree with the President’s statement, my comments were inappropriate and regrettable. I extend sincere apologies to the President for this lack of civility.
Obama later accepted Wilson’s apology. “I’m a big believer that we all make mistakes”, he said. “He apologized quickly and without equivocation and I’m appreciative of that.”
What Joe Wilson did was a total breach of decorum, but he was the only one in the room telling the truth to the American people. It is obvious that the President was lying and the Congressman was telling the truth.