The Department of Labor's new proposal to change the circumstances under which an investment advisor is considered a fiduciary under the Employee Retirement Income Security Act would increase costs and prevent access to retirement planning services, especially for those the lower-and middle-income brackets, according to a study by the Insured Retirement Institute.

More than 30 million households, 27 million of which are from the lowest wealth segment, hold assets in full-service, commission-based IRA accounts, said the IRI.  Under the proposed rule, all advice provided through these brokerage accounts would be illegal. 

As a result, these investors would have to leave their current accounts and switch to either fee-based advisor accounts, for which they would have to meet the minimum balance thresholds, or low-support brokerage accounts.