On Armistice Day (November 11) of 1940, a single storm brought 14,000 claims, the number normally processed in a year. One of every four policyholders suffered losses that year with losses totaling $900,000. By July 1941, the company had concluded that, in the previous year, storms had caused 30,474 claims, all of which had been adjusted by April.
In 1942, the Michigan Mutual Windstorm Insurance Company set its sights on a goal of a half billion dollars in insurance risks and attained it the following year. There were 130,334 policyholders in 1943. More policyholders were added when, in 1945, the company assumed the obligations and membership of the Farmers Mutual Cyclone of Pickford.
After 60 years in business, the president and vice president decided that a major reappraisal project was needed. Many older policies were outdated and inflation had led to underinsurance. On the other hand, some buildings were overinsured, having deteriorated with age. The company hired its first field inspector (a second was hired later that year) with the plan to inspect all insured property and to consolidate buildings into one policy. Some policyholders owned as many as six or eight policies covering that number of separate buildings on their property.