AM Best has revised the outlook to ‘positive’ from ‘stable’ for the long-term issuer credit ratings of members of A.I.M. Mutual Insurance Companies. Those include Associated Industries of Massachusetts Mutual Insurance Company and its reinsured subsidiaries, Associated Employers Insurance Company, Massachusetts Employers Insurance Company, and New Hampshire Employers Insurance Company. The rating agency also affirms the financial strength rating of ‘A’ (Excellent) and the long-term issuer credit ratings of ‘a’ (Excellent) of A.I.M. Mutual’s members. The outlook of the financial strength rating is ‘stable’. The ratings reflect A.I.M. Mutual’s balance sheet strength, which AM Best assesses as ‘strongest’, as well as its adequate operating performance, limited business profile and appropriate enterprise risk management. The group's operational performance drives the positive outlook, as strong underwriting results and investment income contribute to continuous surplus growth. AM Best expects A.I.M. Mutual to continue to outperform its peers on key operating metrics. A.I.M. Mutual specialises in providing workers’ compensation insurance coverage in Massachusetts and New Hampshire.