The claim has been widely criticized. The nonpartisan website PolitiFact selected it as the 2009 "lie of the year."
In defending her original accusation, Palin is not talking about the same policy she originally attacked.
She said Monday that her inflammatory comments in 2009 were about the Independent Payments Advisory Board (IPAB), a group of healthcare experts tasked with cutting Medicare's payments to doctors if the program's spending grows faster than a certain rate.
"Though I was called a liar for calling it like it is, many of these accusers finally saw that Obamacare did in fact create a panel of faceless bureaucrats who have the power to make life and death decisions about health care funding," she wrote Monday.
But Palin's initial comments make no mention of the IPAB. At the time, she referred to a proposal in the House's healthcare bill to have Medicare reimburse doctors for discussing end-of-life planning with their elderly patients.
The House bill did not include the IPAB at all, and in the wake of Palin's remarks, end-of-life planning was axed from the Senate bill that Obama ultimately signed.
— This post was updated at 6:03 p.m.