President Barack Obama said Wednesday that he would be “open and receptive” to “responsible changes” to Obamacare proposed by the new GOP Congress, but asserted that there were some policies that were off the table.

“If in fact one of the item on (the Republican) agenda is to make responsible changes to the ACA to make it work better,” he told reporters during a press conference, “I’m going to be very open and receptive to hearing those ideas.”

But some obvious things would not be open for discussion, Obama said, predictable things like full repeal of the law or repeal of the individual mandate.

“In some cases, recommendations that Republicans have for changes would undermine the structure of the law,” he said. “I’ll be very honest with them about that, ‘The law doesn’t work if you pull out that piece or that piece.'”