According to a Wall Street Journal report, the Department of Labor is looking into an “infrastructure fee” charged by Fidelity to fund firms that sell shares on its platform. The DOL through ERISA has jurisdiction over retirement accounts; the agency has not confirmed the investigation. The issue is whether the fees are adequately disclosed. However, Fidelity representatives said the firm fully complies with disclosure requirements. The WSJ obtained a document that describes the fee, which is calculated as 0.15% of a mutual-fund company’s industrywide assets, and not just on the assets held by Fidelity customers buying shares on the platform. Separately, a plaintiff in a 401(k) fee lawsuit filed last week in Massachusetts federal court claims that Fidelity’s infrastructure fee is prohibited under ERISA and that Fidelity incentivizes funds on its platform to conceal the true nature of such fees. Fidelity has denied the allegations, the WSJ reports. The Massachusetts secretary of the commonwealth’s office is also looking into the fee, according to a report from Bloomberg. According to the Bloomberg report, Massachusetts officials sent a letter to Fidelity requesting: the identity of all Massachusetts pension and retirement plans where Fidelity is a fiduciary or service provider; details of all fees payable by funds to Fidelity; description of the infrastructure fee payable by funds on the network; and the identity of Fidelity units that receive the fee; whether the fee is disclosed to investors, and if so, how the disclosure is provided.