The US Treasury has proposed requiring insurers to hand over underwriting data, broken down by zip code and covering the last five years, in an attempt to assess the potential for “major disruptions” in insurance coverage in some parts of the country.

But business groups have argued the plans would push up costs for insurers, and accused the Treasury of failing to co-ordinate with state-level regulators, in comments submitted before a deadline this week.

The US Chamber of Commerce said the data request presented an “unreasonable burden to insurers”, while the Insurance Information Institute, an industry association representing more than 60 insurance companies, said the request for data would “drive increases in policyholder premium rates”.