The MainStay MacKay U.S. Infrastructure Bond Fund Class I (MGOIX) is a mutual fund that primarily invests in fixed-income securities issued by companies involved in the development and maintenance of infrastructure in the United States. This includes sectors such as transportation, utilities, and public works. The fund aims to provide investors with a steady stream of income through interest payments and potential capital appreciation. It is managed by MainStay Investments and MacKay Shields, two well-established investment firms. As a Class I fund, it typically has a lower expense ratio and requires a higher minimum investment compared to other classes of the same fund.