Truth in Regulations Act of 2017 This bill requires agencies to have written procedures to ensure that an issuance of policy guidance documents (other than regulatory actions) is approved by each appropriate senior agency official unless a supervisor or agency head has agreed to an employee's justification to deviate from the requirements. An agency must also maintain on its website a list of, links to, and a means for the public to comment on and request issuance, modification, or rescission of, such documents. A guidance document may not include mandatory language unless: (1) the agency is describing a statutory or regulatory requirement, (2) the language is addressed to agency employees, or (3) the prohibition against that mandatory language prevents agency consideration of a position advanced by an affected private party. The bill requires agencies to publish drafts of guidance documents for public comment. The bill replaces the "good cause" exception to proposed rulemaking notice and publication requirements with an exception that applies if the agency determines that an imminent threat to public health or safety or a similar exigent circumstance exists. When such exception is applied, the agency, within 18 months after the rule takes effect, shall: (1) provide for a period in which interested persons may submit written data, views, or arguments; and (2) consider such submissions and, if appropriate, repeal or amend the rule.