Congressional Budget Office Cost Estimate: S. 226, Tribal Labor Sovereignty Act 2019 [open pdf - 58KB]
"S. 226 would add Indian tribes to the list of entities that are excluded from the definition of 'employer' for purposes of the National Labor Relations Act. Through the National Labor Relations Board (NLRB), the National Labor Relations Act protects the rights of most private-sector employees to form a union and to bargain collectively. Adding tribes to the list of excluded employers would treat them similarly to state and local governments. Currently, the NLRB generally asserts jurisdiction over the commercial enterprises owned and operated by tribes, even if they are located on a tribal reservation. However, the NLRB does not assert the jurisdiction over tribal enterprises that carry out traditional tribal or governmental functions."
Congressional Budget Office: http://www.cbo.gov/