The Republican measure would make apologies, condolences or expressions of sympathy inadmissible as evidence in civil court, or in administrative hearings concerning the health care provider's actions.
The Wisconsin Medical Society says the protection would encourage more "frank and full communications between a physician and a patient."
But opponents, including the trial attorneys group Wisconsin Association for Justice, argue the change would make it more difficult for people injured by medical malpractice to bring a successful lawsuit.
The GOP-controlled Assembly passed the bill on a voice vote Tuesday. The proposal now goes to the state Senate.