Form 497

Annual Fund Operating Expenses
(ongoing expenses that you pay each year as a
percentage of the value of your investments)^{1, 2}

Management
Fees

Distribution and
Service (12b‑1)
Fees

Other
Expenses³

Total Annual
Fund
Operating
Expenses

iShares^®

iShares Trust

Supplement dated January 29, 2024 (the “Supplement”)

to the currently effective Summary Prospectus, Prospectus

and the Statement of Additional Information (the “SAI”), for the iShares California Muni Bond ETF (CMF) (the “Fund”)

The information in this Supplement updates information in, and should be read in conjunction with, the Summary Prospectus, Prospectus and SAI for the Fund.

The following changes will take effect for the Fund on or around January 29, 2024:

Change in the Fund’s “Fees and Expenses”

The section of the Summary Prospectus and Prospectus entitled “Fees and Expenses” is deleted in its entirety and replaced with the following:

The following table describes the fees and expenses that you will incur if you buy, hold and sell shares of the Fund. The investment advisory agreement between iShares Trust (the “Trust”) and BlackRock Fund Advisors (“BFA”) (the “Investment Advisory Agreement”) provides that BFA will pay all operating expenses of the Fund, except: (i) the management fees, (ii) interest expenses, (iii) taxes, (iv) expenses incurred with respect to the acquisition and disposition of portfolio securities and the execution of portfolio transactions, including brokerage commissions, (v) distribution fees or expenses, and (vi) litigation expenses and any extraordinary expenses.

You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.

^{Operating expenses paid by BFA under the Investment Advisory Agreement exclude acquired fund fees and expenses, if any.}

^{The expense information in the table has been restated to reflect current fees.}

^{The amount rounded to 0.00%.}

Example. This Example is intended to help you compare the cost of owning shares of the Fund with the cost of investing in other funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then sell all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:

Change in the Fund’s “Management”

The third paragraph of the section of the Prospectus entitled “Management” is deleted in its entirety and replaced with the following:

Effective January 29, 2024 BFA is paid a management fee from the Fund, as a percentage of the Fund’s average daily net assets, at the annual rate of 0.08%. Prior to January 29, 2024 and for the fiscal year ended February 28, 2023, BFA was paid a management fee from the Fund, as a percentage of the Fund’s average daily net assets, at the annual rate of 0.25%. BFA may from time to time voluntarily waive and/or reimburse fees or expenses in order to limit total annual fund operating expenses (excluding acquired fund fees and expenses, if any). Any such voluntary waiver or reimbursement may be eliminated by BFA at any time.

Changes in the Fund’s “Investment Advisory, Administrative and Distribution Services”

In the Management Fee table on pages 177‑179 of the SAI, the following footnote is added to the Fund, as new footnote seven (7) and the current footnotes (7) through (18) are renumbered accordingly:

Effective January 29, 2024, the management fee for the iShares California Muni Bond ETF is 0.08%. Prior to January 29, 2024, the management fee for the iShares California Muni Bond ETF was 0.25%.

If you have any questions, please call 1‑800‑iShares (1‑800‑474‑2737).

iShares^® is a registered trademark of BlackRock Fund Advisors and its affiliates.

IS‑SUPP‑CMF‑0124

PLEASE RETAIN THIS SUPPLEMENT

FOR FUTURE REFERENCE