A Prospectus Supplement filing for the UBS Money Series' UBS Select Prime Preferred Fund and UBS Select Government Preferred Fund allows the former to invest more in municipal securities and extends fee waivers for the latter. It says, "First, this supplement updates certain information contained in the Prospectus for UBS Select Prime Preferred Fund. Effective January 17, 2017, the fund will be permitted to invest in municipal securities without limitation. Currently, the fund may invest up to 5% of its net assets in such investments, which have more recently become more attractive because of market changes. The fund is not expected to be able to "pass through" the tax-exempt nature of interest from such investments; however, they may be more attractive relative to other potential fund investments even without taking such tax advantage into account. Additionally, this supplement updates certain information contained in the Prospectus regarding a voluntary fee waiver for the fund. Second, this supplement updates certain information contained in the Prospectus regarding a voluntary fee waiver for UBS Select Government Preferred Fund." The filing explains, "Effective January 1, 2017, UBS Asset Management (Americas) Inc. ("UBS AM") will continue to voluntarily waive 0.06% of its management fee (imposed at the related master fund level) and 0.04% of its administrative fees (imposed at the feeder fund level) until January 31, 2017 in order to continue to voluntarily reduce the fund's expenses by 0.10% until January 31, 2017. These voluntary fee waivers are in addition to the pre-existing contractual fee waiver arrangements that cap the fund's ordinary operating expense ratio at 0.14% through August 31, 2017; the contractual cap is not being increased. The aggregate impact of both the voluntary fee waivers and the contractual fee waiver is to reduce the fund's ordinary operating expense ratio to 0.04% until January 31, 2017.... UBS AM may further voluntarily waive fees and/or reimburse expenses from time to time. For example, UBS AM may voluntarily undertake to waive fees and/or reimburse expenses in the event that fund yields drop below a certain level. Once started, there is no guarantee that UBS AM would continue to voluntarily waive a portion of its fees and/or reimburse expenses. Waivers/reimbursements may impact the fund's performance."