Minn. Stat. § 14.49

When regularly appointed administrative law judges are not available, the chief administrative law judge may contract with qualified individuals to serve as administrative law judges. Such temporary administrative law judges shall not be employees of the state. Compensation judges must be employees of the state, except in the following instances: (1) when all available regularly appointed compensation judges are disqualified from a specific case under the Code of Judicial Conduct, the chief administrative law judge may contract with a workers' compensation attorney or former workers' compensation judge to serve as a compensation judge for that case; and (2) when regularly appointed workers' compensation judges are not available to hear pending cases on a timely basis, the chief administrative law judge may contract with a retired workers' compensation judge, formerly an employee of the state, to serve as a workers' compensation judge.