If a business needs to provide workers compensation coverage for states other than the residence state of the business, other than their primary state where they are located and work, workers compensation policies can be amended to provide the coverage required.
For many years, this coverage was endorsed onto workers compensation policies by adding an "All States Endorsement." This endorsement has not been available since the mid 1980'S. So don't be confused by out dated terms. Fact is an endorsement is no longer required to provide coverage in the states listed in the declaration. Look for Item 3A and 3C to provide the "all states" wording on current policies and when properly used automatic coverage will apply in all except the monopolistic fund states.
Monopolistic fund states require that workers compensation coverage be purchased from the state fund. Monopolistic fund states, with the exception of North Dakota, do not have a provision for providing an "all states" provision.
When Item 3A and 3C of the policy is correctly used it will be noted on the workers comp policy declarations pages as to the states coverage applies. So to verify that "all states" coverage exists on a specific policy just check the declarations page, it should be obvious.