# EDGAR Filing Document

**Accession Number:** 0001060517
**File Stem:** 0001410368-26-057290
**Filing Date:** 2026-6
**Character Count:** 13456
**Document Hash:** c252a2498da6ac43affb052299db83a9
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001410368-26-057290.hdr.sgml**: 20260605

**ACCESSION NUMBER**: 0001410368-26-057290

**CONFORMED SUBMISSION TYPE**: N-MFP3

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20260531

**FILED AS OF DATE**: 20260605

**DATE AS OF CHANGE**: 20260605

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** UBS Series Funds
- **CENTRAL INDEX KEY:** 0001060517

**ORGANIZATION NAME:**
- **EIN:** 134010447
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 0430

**FILING VALUES:**
- **FORM TYPE:** N-MFP3
- **SEC ACT:** 1940 Act
- **SEC FILE NUMBER:** 811-08767
- **FILM NUMBER:** 261068593

**BUSINESS ADDRESS:**
- **STREET 1:** C/O UBS ASSET MANAGEMENT (AMERICAS) LLC
- **STREET 2:** 1285 AVENUE OF THE AMERICAS
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10019
- **BUSINESS PHONE:** 212-821-3000

**MAIL ADDRESS:**
- **STREET 1:** C/O UBS ASSET MANAGEMENT (AMERICAS) LLC
- **STREET 2:** 1285 AVENUE OF THE AMERICAS
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10019

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** UBS MONEY SERIES
- **DATE OF NAME CHANGE:** 20020716

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** BRINSON MONEY SERIES
- **DATE OF NAME CHANGE:** 20010625

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MITCHELL HUTCHINS LIR MONEY SERIES
- **DATE OF NAME CHANGE:** 19990730

## Series and Classes Contracts Data

### UBS Select Government Preferred Fund (Series ID: S000053132)

| Class ID   | Class Name                           | Ticker Symbol   |
|:---|:---|:---|
| C000167200 | UBS Select Government Preferred Fund | SGPXX           |

# Form N-MFP3: Monthly Schedule of Portfolio Holdings

## N-MFP: Filer Information
**Submission Type:** N-MFP3
**CIK:** 0001060517

### General Information

**Report for (YYYY-MM-DD):** 2026-05-31

**Registrant Full Name:** UBS Series Funds

**CIK Number of Registrant:** 0001060517

**LEI of Registrant:** 54930058UKPXVB81RJ71

**Name of Series:** UBS Select Government Preferred Fund

**LEI of Series:** 549300TPU9BIV8MJY882

**EDGAR Series Identifier:** S000053132

**Total number of share classes in the series:** 1

**Is this the fund's final filing on Form N-MFP?:** No

**Has the fund acquired or merged with another fund?:** No

## Part A: Series-Level Information about the Fund

### Service Providers
| Role                          | Details                                                      | File/CIK Number   |
|:---|:---|:---|
| Investment Adviser            | UBS ASSET MANAGEMENT (AMERICAS) LLC                          | 801-34910         |
| Independent Public Accountant | Ernst & Young  LLP<br>City: New York<br>State: NY            |  |
| Administrator                 | UBS ASSET MANAGEMENT (AMERICAS) LLC                          |  |
| Transfer Agent                | BNY Mellon Investment Servicing (US) Inc.<br>CIK: 0000849542 | 084-01761         |

### Fund Characteristics & Assets

- **Securities Act File Number:** 333-52965

- **Is this a Feeder Fund?:** Yes

- **Is this a Master Fund?:** No

- **Is this series for insurance company separate accounts?:** No

- **Money Market Fund Category:** Government

- **Is this a Retail Money Market Fund?:** No

- **Is this a Government Money Market Fund?:** No

- **WAM:** 1 days

- **WAL:** 1 days

- **Total Value of Portfolio Securities:** $12515032707.35

- **Amortized Cost of Portfolio Securities:** $0.00

- **Cash:** $0.00

- **Total Other Assets:** $0.00

- **Total Liabilities:** $37140527.51

- **Net Assets of Series:** $12477892179.84

- **Number of Shares Outstanding (Series):** 12477552526.5300

- **Does the fund seek to maintain a stable price per share?:** Yes

- **Stable Price Per Share:** $1.00

- **Is cash management vehicle an affiliated fund?:** No

- **Does the fund apply liquidity fees?:** No

### Daily & Weekly Liquid Assets
| Date       | Daily Liquid Assets ($)   | Weekly Liquid Assets ($)   | Daily Liquid Assets (%)   | Weekly Liquid Assets (%)   |
|:---|:---|:---|:---|:---|
| 2026-05-01 | $12948917725.07           | $14418400507.33            | 52.4500%                  | 58.4000%                   |
| 2026-05-04 | $13330519042.68           | $14970413498.08            | 52.9200%                  | 59.4300%                   |
| 2026-05-05 | $12767479043.88           | $14407519818.97            | 51.8400%                  | 58.5000%                   |
| 2026-05-06 | $12976820179.08           | $14617008583.65            | 52.2500%                  | 58.8500%                   |
| 2026-05-07 | $12399422717.48           | $14039773359.46            | 51.1100%                  | 57.8700%                   |
| 2026-05-08 | $12341582901.92           | $14046074509.28            | 50.9800%                  | 58.0200%                   |
| 2026-05-11 | $13052092436.52           | $14885269154.00            | 52.3800%                  | 59.7300%                   |
| 2026-05-12 | $12765999443.53           | $14428353126.27            | 52.1800%                  | 58.9800%                   |
| 2026-05-13 | $12949753387.03           | $14612241165.16            | 52.3500%                  | 59.0700%                   |
| 2026-05-14 | $12433737193.30           | $14231699249.62            | 51.4800%                  | 58.9300%                   |
| 2026-05-15 | $12743201580.90           | $14667317957.97            | 52.0900%                  | 59.9600%                   |
| 2026-05-18 | $13028677962.31           | $15609350410.48            | 52.6500%                  | 63.0800%                   |
| 2026-05-19 | $12930709703.13           | $15511615268.69            | 52.2100%                  | 62.6300%                   |
| 2026-05-20 | $13013771369.12           | $15594900855.98            | 52.3700%                  | 62.7500%                   |
| 2026-05-21 | $12405329965.58           | $14860674096.37            | 51.1800%                  | 61.3100%                   |
| 2026-05-22 | $11772369684.10           | $14227937793.13            | 49.8600%                  | 60.2600%                   |
| 2026-05-26 | $12192231215.12           | $15237950830.64            | 50.7500%                  | 63.4200%                   |
| 2026-05-27 | $12674501009.13           | $15720467444.27            | 51.7100%                  | 64.1400%                   |
| 2026-05-28 | $12484807199.73           | $15318053279.37            | 51.7900%                  | 63.5400%                   |
| 2026-05-29 | $12342679593.90           | $15176189895.50            | 51.4900%                  | 63.3100%                   |

### 7-Day Gross Yield
| Date       | 7-Day Gross Yield   |
|:---|:---|
| 2026-05-01 | 3.7000%             |
| 2026-05-04 | 3.6900%             |
| 2026-05-05 | 3.6900%             |
| 2026-05-06 | 3.6900%             |
| 2026-05-07 | 3.6800%             |
| 2026-05-08 | 3.6700%             |
| 2026-05-11 | 3.6700%             |
| 2026-05-12 | 3.6700%             |
| 2026-05-13 | 3.6700%             |
| 2026-05-14 | 3.6700%             |
| 2026-05-15 | 3.6600%             |
| 2026-05-18 | 3.6600%             |
| 2026-05-19 | 3.6500%             |
| 2026-05-20 | 3.6500%             |
| 2026-05-21 | 3.6400%             |
| 2026-05-22 | 3.6400%             |
| 2026-05-26 | 3.6500%             |
| 2026-05-27 | 3.6500%             |
| 2026-05-28 | 3.6600%             |
| 2026-05-29 | 3.6800%             |

### Daily Net Asset Value per Share (Series)
| Date       | Net Asset Value per Share   |
|:---|:---|
| 2026-05-01 | 0.9999                      |
|  |  |
| 2026-05-04 | 1.0000                      |
|  |  |
| 2026-05-05 | 1.0000                      |
|  |  |
| 2026-05-06 | 1.0000                      |
|  |  |
| 2026-05-07 | 1.0000                      |
|  |  |
| 2026-05-08 | 1.0000                      |
|  |  |
| 2026-05-11 | 1.0000                      |
|  |  |
| 2026-05-12 | 1.0000                      |
|  |  |
| 2026-05-13 | 1.0000                      |
|  |  |
| 2026-05-14 | 1.0000                      |
|  |  |
| 2026-05-15 | 0.9999                      |
|  |  |
| 2026-05-18 | 1.0000                      |
|  |  |
| 2026-05-19 | 1.0000                      |
|  |  |
| 2026-05-20 | 1.0000                      |
|  |  |
| 2026-05-21 | 1.0000                      |
|  |  |
| 2026-05-22 | 0.9999                      |
|  |  |
| 2026-05-26 | 1.0000                      |
|  |  |
| 2026-05-27 | 1.0000                      |
|  |  |
| 2026-05-28 | 1.0000                      |
|  |  |
| 2026-05-29 | 0.9999                      |
|  |  |

## Part B: Class-Level Information about the Fund

### Class: Basis A

- **Minimum Initial Investment:** $50000000.00

- **Net Assets of Class:** $12477892179.84

- **Number of Shares Outstanding:** 12477552526.5300

- **Expense Reimbursement/Waiver:** 428695.00

**Daily Net Asset Value per Share (Class)**
| Date       | NAV per Share   |
|:---|:---|
| 2026-05-01 | 0.9999          |
|  |  |
| 2026-05-04 | 1.0000          |
|  |  |
| 2026-05-05 | 1.0000          |
|  |  |
| 2026-05-06 | 1.0000          |
|  |  |
| 2026-05-07 | 1.0000          |
|  |  |
| 2026-05-08 | 1.0000          |
|  |  |
| 2026-05-11 | 1.0000          |
|  |  |
| 2026-05-12 | 1.0000          |
|  |  |
| 2026-05-13 | 1.0000          |
|  |  |
| 2026-05-14 | 1.0000          |
|  |  |
| 2026-05-15 | 0.9999          |
|  |  |
| 2026-05-18 | 1.0000          |
|  |  |
| 2026-05-19 | 1.0000          |
|  |  |
| 2026-05-20 | 1.0000          |
|  |  |
| 2026-05-21 | 1.0000          |
|  |  |
| 2026-05-22 | 0.9999          |
|  |  |
| 2026-05-26 | 1.0000          |
|  |  |
| 2026-05-27 | 1.0000          |
|  |  |
| 2026-05-28 | 1.0000          |
|  |  |
| 2026-05-29 | 0.9999          |
|  |  |

**Daily Shareholder Flows**
| Date       | Gross Subscriptions ($)   | Gross Redemptions ($)   |
|:---|:---|:---|
| 2026-05-01 | $402089013.15             | $231224058.83           |
| 2026-05-04 | $319218979.48             | $321640522.98           |
| 2026-05-05 | $107069115.40             | $159061542.15           |
| 2026-05-06 | $93867564.60              | $90727029.63            |
| 2026-05-07 | $55712560.88              | $209038333.77           |
| 2026-05-08 | $111795416.36             | $74743322.40            |
| 2026-05-11 | $458162276.69             | $124454465.81           |
| 2026-05-12 | $103828414.00             | $462342145.38           |
| 2026-05-13 | $57120816.03              | $121128720.67           |
| 2026-05-14 | $155966862.37             | $101377403.22           |
| 2026-05-15 | $312152242.40             | $204980440.35           |
| 2026-05-18 | $137254506.55             | $257834856.48           |
| 2026-05-19 | $209545949.45             | $59731312.23            |
| 2026-05-20 | $55453365.79              | $160760863.89           |
| 2026-05-21 | $39600816.72              | $273778993.28           |
| 2026-05-22 | $63480740.00              | $503756647.08           |
| 2026-05-26 | $243130488.11             | $83737855.43            |
| 2026-05-27 | $246347113.50             | $55917397.31            |
| 2026-05-28 | $356666316.58             | $192133601.10           |
| 2026-05-29 | $270579351.51             | $357724748.14           |

**Total Gross Subscriptions (Month):** $3799041909.57

**Total Gross Redemptions (Month):** $4046094260.13

**7-Day Net Yield (Class)**
| Date       | 7-Day Net Yield   |
|:---|:---|
| 2026-05-01 | 3.5600%           |
| 2026-05-04 | 3.5500%           |
| 2026-05-05 | 3.5500%           |
| 2026-05-06 | 3.5500%           |
| 2026-05-07 | 3.5400%           |
| 2026-05-08 | 3.5300%           |
| 2026-05-11 | 3.5300%           |
| 2026-05-12 | 3.5300%           |
| 2026-05-13 | 3.5300%           |
| 2026-05-14 | 3.5300%           |
| 2026-05-15 | 3.5200%           |
| 2026-05-18 | 3.5200%           |
| 2026-05-19 | 3.5100%           |
| 2026-05-20 | 3.5100%           |
| 2026-05-21 | 3.5000%           |
| 2026-05-22 | 3.5000%           |
| 2026-05-26 | 3.5100%           |
| 2026-05-27 | 3.5100%           |
| 2026-05-28 | 3.5200%           |
| 2026-05-29 | 3.5400%           |

**Beneficial/Record Owner Categories**
| Category   | Other Category   | Record Owner %   | Beneficial Owner %   |
|:---|:---|:---|:---|
| Other      | IND FID AS EXEC  | 14.4200%         | 0.0000%              |

## Part C: Schedule of Portfolio Securities

### Security 1: Government Master Fund

- **C.1 - Title:** Government Master Fund
- **C.6 - Investment Category:** Investment Company
- **Identifiers:** C.3 - CUSIP: 976WHL907, C.3 - LEI: 54930015XY4J2ENG8G36, C.5 - Other ID: 976WHL907
- **C.18 - Value (incl. sponsor support):** $12515032707.35
- **C.18.a - Value (excl. sponsor support):** $12515032707.35
- **C.19 - Percentage of Net Assets:** 100.0000%
- **C.17 - Yield as of Reporting Date:** 0.0000%
- **C.11 - Maturity Date (WAM):** 2026-06-01
- **C.12 - Maturity Date (WAL):** 2026-06-01
- **C.13 - Final Legal Maturity Date:** 2026-06-01
- **Characteristics:** C.9 Eligible Security? Yes, C.14 Has Demand Feature? No, C.15 Has Guarantee? No, C.16 Has Enhancement? No, C.22 Is an Illiquid Security? No, C.20 Is a Daily Liquid Asset? Yes, C.21 Is a Weekly Liquid Asset? Yes, C.23 Categorized at Level 3? No

## N-MFP: Signatures

**Registrant:** UBS Series Funds

**Date:** 2026-06-05

**By:** /s/Rose Ann Bubloski

**Name of Signing Officer:** Rose Ann Bubloski

**Title of Signing Officer:** Vice President