# EDGAR Filing Document

**Accession Number:** 0000893818
**File Stem:** 0001410368-25-032147
**Filing Date:** 2025-11
**Character Count:** 9076
**Document Hash:** fb12812df53e0bb76e46320ee3989f91
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001410368-25-032147.hdr.sgml**: 20251126

**ACCESSION NUMBER**: 0001410368-25-032147

**CONFORMED SUBMISSION TYPE**: NPORT-P

**PUBLIC DOCUMENT COUNT**: 2

**CONFORMED PERIOD OF REPORT**: 20250930

**FILED AS OF DATE**: 20251126

**DATE AS OF CHANGE**: 20251126

**PERIOD START**: 20251231

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** BlackRock Funds III
- **CENTRAL INDEX KEY:** 0000893818

**ORGANIZATION NAME:**
- **EIN:** 000000000
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** NPORT-P
- **SEC ACT:** 1940 Act
- **SEC FILE NUMBER:** 811-07332
- **FILM NUMBER:** 251525875

**BUSINESS ADDRESS:**
- **STREET 1:** 400 HOWARD STREET
- **CITY:** SAN FRANCISCO
- **STATE:** CA
- **ZIP:** 94105
- **BUSINESS PHONE:** 8006439691

**MAIL ADDRESS:**
- **STREET 1:** 400 HOWARD STREET
- **CITY:** SAN FRANCISCO
- **STATE:** CA
- **ZIP:** 94105

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** BARCLAYS GLOBAL INVESTORS FUNDS
- **DATE OF NAME CHANGE:** 20060201

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** BARCLAYS GLOBAL INVESTORS FUNDS INC
- **DATE OF NAME CHANGE:** 19990804

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MASTERWORKS FUNDS INC
- **DATE OF NAME CHANGE:** 19960607

## Series and Classes Contracts Data

### iShares S&P 500 Index Fund (Series ID: S000004272)

| Class ID   | Class Name           | Ticker Symbol   |
|:---|:---|:---|
| C000011979 | Class K Shares       | WFSPX           |
| C000117725 | Investor A Shares    |  |
| C000117726 | Institutional Shares |  |
| C000117728 | Service Shares       |  |
| C000201951 | Investor P Shares    |  |
| C000212062 | Class G Shares       |  |

## Nport-Ex

September 30, 2025

2025 Quarterly Report <br>&nbsp;&nbsp;&nbsp;&nbsp;(Unaudited)<br>

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

---

| |
|:---|
| **BlackRock Funds III** |
| • iShares S&P 500 Index Fund |

---

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

**Not FDIC Insured • May Lose Value • No Bank Guarantee**<br>

------

Schedule of Investments (unaudited)

September 30, 2025

**iShares S&P 500 Index Fund** 

**(Percentages shown are based on Net Assets)**

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

---

| | |
|:---|:---|
| *Mutual Fund* | *Value* |
| S&P 500 Index Master Portfolio of Master Investment Portfolio | &nbsp;&nbsp; $52027883521 |
| **Total Investments — 100.1%** <br>**(Cost: $17,745,336,013)** | &nbsp;&nbsp; 52027883521 |
| **Liabilities in Excess of Other Assets — (0.1)%** | &nbsp;&nbsp; (33456159)<br>|
| **Net Assets — 100.0%** | &nbsp;&nbsp; $51994427362 |

---

iShares S&P 500 Index Fund (the "Fund") seeks to achieve its investment objective by investing all of its assets in S&P 500 Index Master Portfolio (the "Master Portfolio"), which has the same investment objective and strategies as the Fund. As of September 30, 2025, the value of the investment and the percentage owned by the Fund of the Master Portfolio was $52,027,883,521 and 98.8%, respectively.

The Fund records its investment in the Master Portfolio at fair value. The Fund's investment in the Master Portfolio is valued pursuant to the pricing policies approved by the Board of Trustees of the Master Portfolio.

**Fair Value Hierarchy as of Period End**

Various inputs are used in determining the fair value of financial instruments at the measurement date. These inputs to valuation techniques are categorized into a fair value hierarchy consisting of three broad levels for financial reporting purposes as follows:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;• Level 1 – Unadjusted price quotations in active markets/exchanges that the Fund has the ability to access for identical assets or liabilities;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;• Level 2 – Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly; and

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;• Level 3 – Inputs that are unobservable and significant to the entire fair value measurement for the asset or liability (including the Valuation Committee's assumptions used in determining the fair value of financial instruments).

The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). Accordingly, the degree of judgment exercised in determining fair value is greatest for instruments categorized in Level 3. The inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, for disclosure purposes, the fair value hierarchy classification is determined based on the lowest level input that is significant to the fair value measurement in its entirety. Investments classified within Level 3 have significant unobservable inputs used by the Valuation Committee in determining the price for Fair Valued Investments. Level 3 investments include equity or debt issued by privately held companies or funds that may not have a secondary market and/or may have a limited number of investors. The categorization of a value determined for financial instruments is based on the pricing transparency of the financial instruments and is not necessarily an indication of the risks associated with investing in those securities. For information about the Fund's policy regarding valuation of financial instruments, refer to its most recent financial statements.

Certain investments of the Fund were fair valued using net asset value ("NAV") as a practical expedient as no quoted market value is available and therefore have been excluded from the fair value hierarchy.

------

## Form NPORT-P: Monthly Portfolio Investments Report

### NPORT-P: Part A: General Information

**Item A.1. Information about the Registrant.**

- **a. Name of Registrant:** BlackRock Funds III

- **b. Investment Company Act file number:** 811-07332

- **c. CIK number of Registrant:** 0000893818

- **d. LEI of Registrant:** 5493008LW2651I1QB503

- **e. Address and telephone number of Registrant.**

  - **Street Address 1:** 100 Bellevue Parkway

  - **City:** Wilmington

  - **State:** DE

  - **Foreign country:** US

  - **Zip / Postal Code:** 19809

  - **Telephone number:** 800-441-7762

**Item A.2. Information about the Series.**

- **a. Name of Series:** iShares S&P 500 Index Fund

- **b. EDGAR series identifier (if any):** S000004272

- **c. LEI of Series:** 54930044UW5DQ1DX0D35

**Item A.3. Reporting period.**

- **a. Date of fiscal year-end:** 2025-12-31

- **b. Date as of which information is reported:** 2025-09-30

**Item A.4. Final filing**

Does the Fund anticipate that this will be its final filing on Form N-PORT? **No**

### Fund Information

**Total Assets:** $52075823115.25

**Total Liabilities:** $191178675.00

**Net Assets:** $51884644440.25

**Monthly Return Information**

| Class               | Month 1 Return (%)   | Month 2 Return (%)   | Month 3 Return (%)   |
|:---|:---|:---|:---|
| Class ID C000201951 | 2.21%                | 2.00%                | 3.62%                |
| Class ID C000212062 | 2.25%                | 2.03%                | 3.65%                |
| Class ID C000117728 | 2.23%                | 2.01%                | 3.63%                |
| Class ID C000117725 | 2.21%                | 2.00%                | 3.61%                |
| Class ID C000011979 | 2.24%                | 2.02%                | 3.65%                |
| Class ID C000117726 | 2.24%                | 2.02%                | 3.63%                |

**Monthly Gains & Losses**

| Period   | Net Realized Gain/Loss   | Net Unrealized Appreciation/Depreciation   |
|:---|:---|:---|
| Month 1  | $0.00                    | $0.00                                      |
| Month 2  | $0.00                    | $0.00                                      |
| Month 3  | $0.00                    | $0.00                                      |

### Schedule of Portfolio Investments

| Name                        | Title                          | Identifiers                                   | Payoff Profile   | Asset Category   | Issuer Category   | Country   |   Balance | Units   | Value (USD)     | % of Net Assets   | Maturity Date   | Coupon Type   | Annualized Rate (%)   | Restricted?   | Fair Value Level   | Lending Status   |
|:---|:---|:---|:---|:---|:---|:---|---:|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| MASTER INVESTMENT PORTFOLIO | S&P 500 Index Master Portfolio | CUSIP: 000000000<br>LEI: 5493004HQXF0DFT60U28 | Long             | EC               | RF                | US        |  85495385 | NS      | $52058242494.86 | 100.33%           |  |  |  | No            | N/A                | On Loan: No      |

### Signature

**Date Signed:** 2025-10-29

**Name of Applicant:** BlackRock Funds III

**Signature:** Chuck Pulsfort

**Name of Signer:** Chuck Pulsfort

**Title:** Assistant Treasurer