U.S. healthcare stocks were mixed Monday at the market close after President Trump promised that Senate Republicans will "fulfill the solemn promise" to repeal and replace Obamacare.

Shares of Aetna Inc (AET) , UnitedHealth Group (UNH) - Get Report  and Humana Inc (HUM) - Get Report   closed lower, while Cigna Corp (CI) - Get Report  and Anthem Inc (ANTM) - Get Report  closed higher.

There will be a Senate vote on a motion to proceed tomorrow. Should it pass, the Senate will have 20 hours to add, edit and delete from the House's version of the American Healthcare Act.

President Trump promised to repeal and replace Obamacare, adding that the new version of U.S. healthcare law will allow for tax credits for private plans and $45 billion to fight the opioid crisis.

Trump added that Republicans will need a vote from every member of the GOP in the Senate to move forward. He called the Senate Democrats "obstructionists."

President Trump took to Twitter (TWTR) - Get Report Monday in a call to action for Republican lawmakers.

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