In April 2017, Baldwin was one of five Democratic senators to sign a letter to President Trump warning that failure "to take immediate action to oppose the lawsuit or direct House Republicans to forgo this effort will increase instability in the insurance market, as insurers may choose not to participate in the marketplace in 2018" and that they remained concerned that his administration "has still not provided certainty to insurers and consumers that you will protect the cost-sharing subsidies provided under the law."