'Single-Payer Language in the Bill'

Interesting recap from today's meeting at the White House between the president and House progressives:

But, said one attendee, Obama pointed Kucinich toward single-payer language that Sen. Bernie Sanders (I-Vt.) was able to get into the bill. Kucinich fought for an amendment that would allow states to adopt single-payer systems without getting sued by insurance companies. Obama told Kucinich that Sanders's measure was similar but doesn't kick in for several years. "He definitely wrote it down," said one member of Kucinich, suggesting that he'd look into it.

I'm admittedly unaware of any single-payer language in the bill. Anyone else know what the president is referring to? I recall something about laying the groundwork for state-based single-payer systems, but I honestly don't know where that ended up. Could it be the Sanders amendment?