[1995] DeWitt v. Continental Ins. and Old Republic Ins. [2/19/04] 2004 MTWCC 10 Section 39-71-403(1), MCA (1995-2001), requires a claimant to file an occupational disease claim "within 1 year from the date the claimant knew or should have known that the claimant's condition resulted from an occupational disease." The period may be waived for an additional two years but no more. § 39-71-403(2), MCA (1995-2001).