But supporters, including hospital groups and others, argued the federal money would help alleviate uncompensated care that drives up costs for others. They also say it would provide insurance to the working poor who can't otherwise afford it.
A provision of the federal healthcare law provides the bulk of the money for such expansion.
The governor mentioned that possibilities for expanding Medicaid include a brewing ballot initiative that could go to voters in 2014. The governor also did not rule out calling a special session of the Legislature.
The legislation was the focus of intense debate earlier this year, and barely cleared initial votes in both chambers before Republican leaders stuffed it into a committee to avoid final votes.
"We should remember the fact that majorities in both chambers that supported it. It was procedural, scheduling, that prevented it from getting a full vote on the House floor," Bullock said.
A coalition called the Healthy Montana Initiative said it is still drafting proposed language for a ballot measure it hopes to submit in about a month so state officials can approve the language before signature-gathering can begin.
The group said that is still would prefer for the Legislature to come back and approve expansion so it can take effect as other parts of the healthcare law going into place in 2014.