OLDWICK, N.J.--(BUSINESS WIRE)-- #insurance--AM Best has affirmed the Financial Strength Rating of A- (Excellent) and the Long-Term Issuer Credit Rating of “a-” (Excellent) of Michigan Professional Insurance Exchange (MPIE) (Grand Rapids, MI). The outlook of these Credit Ratings (ratings) is stable. Concurrently, AM Best has withdrawn these ratings as the company has requested to no longer participate in AM Best’s interactive rating process. The ratings reflect MPIE’s balance sheet strength, which AM Best a