The Isle of Man TT Marshals Association says it's receiving a large number of enquiries about the ending of the Reciprocal Health Agreement between the Isle of Man and the UK.
The organisation relies heavily on visitors volunteering to help out over the fortnight.
As in previous years, whilst on duty all marshals will be covered by a scheme organised by the Auto Cycle Union.
However, they will not be covered for on-going medical treatment if they are injured or fall ill during the rest of their stay.
Former chairman of the Association and now Press Officer Bill Carden says it is a worrying situation.