BLACKROCK CALIFORNIA MUNICIPAL SERIES TRUST
BlackRock California Municipal Opportunities Fund
(the “Fund”)
Supplement dated October 4, 2023 (the “Supplement”) to the Fund’s
Summary Prospectuses and Prospectuses, each dated September 28, 2023, as supplemented to date
The following changes are made to the Fund’s Summary Prospectuses and Prospectuses, as applicable:
The section of the Summary Prospectuses entitled “Key Facts About BlackRock California Municipal Opportunities Fund — Portfolio Managers” and the section of the Prospectuses entitled “Fund Overview — Key Facts About BlackRock California Municipal Opportunities Fund — Portfolio Managers” are deleted in their entirety and replaced with the following:
Portfolio Managers
| Name | Portfolio Manager of the Fund Since |
Title | ||
| Walter O’Connor, CFA | 1993 | Managing Director of BlackRock, Inc. | ||
| Peter Hayes1 | 2015 | Managing Director of BlackRock, Inc. | ||
| Michael Kalinoski, CFA | 2015 | Director of BlackRock, Inc. | ||
| Kevin Maloney, CFA | 2022 | Director of BlackRock, Inc. | ||
| Ryan McDonald, CFA | 2023 | Managing Director of BlackRock, Inc. | ||
| Sean Carney | 2023 | Managing Director of BlackRock, Inc. |
| 1 | During the first quarter of 2024, Peter Hayes will retire from BlackRock, Inc., and will no longer serve as a portfolio manager of the Fund. |
The section of the Prospectuses entitled “Details About the Funds — How Each Fund Invests — About the Portfolio Management Team of the California Fund” is deleted in its entirety and replaced with the following:
| ABOUT THE PORTFOLIO MANAGEMENT TEAM OF THE CALIFORNIA FUND |
| The California Fund is managed by a team of financial professionals. Walter O’Connor, CFA, Peter Hayes1, Michael Kalinoski, CFA, Kevin Maloney, CFA, Ryan McDonald, CFA, and Sean Carney, are the co-portfolio managers and are jointly and primarily responsible for the day-to-day management of the Fund. Please see “Management of the Funds — Portfolio Manager Information” for additional information about the portfolio management team. |
| 1 | During the first quarter of 2024, Peter Hayes will retire from BlackRock, Inc., and will no longer serve as a portfolio manager of the Fund. |
The section of the Prospectuses entitled “Management of the Funds — Portfolio Manager Information — California Fund” is deleted in its entirety and replaced with the following:
California Fund
The Fund is managed by a team of financial professionals. Walter O’Connor, CFA, Peter Hayes, Michael Kalinoski, CFA, Kevin Maloney, CFA, Ryan McDonald, CFA, and Sean Carney, are the co-portfolio managers and are jointly and primarily responsible for the day-to-day management of the Fund.
| Portfolio Manager | Primary Role | Since | Title and Recent Biography | |||
| Walter O’Connor, CFA, Co-portfolio manager | Jointly and primarily responsible for the day-to-day management of the Fund’s portfolio, including setting the Fund’s overall investment strategy and overseeing the management of the Fund. | 1993 | Managing Director of BlackRock, Inc. since 2006. | |||
| Peter Hayes1, Co-portfolio manager | Jointly and primarily responsible for the day-to-day management of the Fund’s portfolio, including setting the Fund’s overall investment strategy and overseeing the management of the Fund. | 2015 | Managing Director of BlackRock, Inc. since 2006; Head of Municipal Bonds within BlackRock Fixed Income Portfolio Management Group since 2006. | |||
| Michael Kalinoski, CFA, Co-portfolio manager | Jointly and primarily responsible for the day-to-day management of the Fund’s portfolio, including setting the Fund’s overall investment strategy and overseeing the management of the Fund. | 2015 | Director of BlackRock, Inc. since 2006. | |||
| Kevin Maloney, CFA, Co-portfolio manager | Jointly and primarily responsible for the day-to-day management of the Fund’s portfolio, including setting the Fund’s overall investment strategy and overseeing the management of the Fund. | 2022 | Director of BlackRock, Inc. since 2021; Vice President of BlackRock, Inc. from 2018 to 2020. | |||
| Ryan McDonald, CFA, Co-portfolio manager | Jointly and primarily responsible for the day-to-day management of the Fund’s portfolio, including setting the Fund’s overall investment strategy and overseeing the management of the Fund. | 2023 | Managing Director of BlackRock, Inc. since 2023; Director of BlackRock, Inc. from 2017 to 2022. | |||
| Sean Carney, Co-portfolio manager | Jointly and primarily responsible for the day-to-day management of the Fund’s portfolio, including setting the Fund’s overall investment strategy and overseeing the management of the Fund. | 2023 | Managing Director of BlackRock, Inc. since 2018. |
| 1 | During the first quarter of 2024, Peter Hayes will retire from BlackRock, Inc., and will no longer serve as a portfolio manager of the Fund. |
Shareholders should retain this Supplement for future reference.
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