Jun. 08, 2020

BlackRock Funds IV

BlackRock Global Long/Short Credit Fund

BlackRock Systematic ESG Bond Fund

BlackRock Systematic Multi-Strategy Fund

BlackRock Funds V

BlackRock Core Bond Portfolio

BlackRock Emerging Markets Bond Fund

BlackRock Emerging Markets Flexible Dynamic Bond Portfolio

BlackRock Floating Rate Income Portfolio

BlackRock High Yield Bond Portfolio

BlackRock Income Fund

BlackRock Inflation Protected Bond Portfolio

BlackRock Low Duration Bond Portfolio

BlackRock Strategic Income Opportunities Portfolio

BlackRock U.S. Government Bond Portfolio

BlackRock Funds VI

BlackRock CoreAlpha Bond Fund

BlackRock Global Allocation Fund, Inc.

BlackRock Index Funds, Inc.

iShares MSCI EAFE International Index Fund

BlackRock Large Cap Focus Growth Fund, Inc.

BlackRock Large Cap Series Funds, Inc.

BlackRock Event Driven Equity Fund

BlackRock Latin America Fund, Inc.

BlackRock Long-Horizon Equity Fund

BlackRock Mid Cap Dividend Series, Inc.

BlackRock Mid Cap Dividend Fund

BlackRock Natural Resources Trust

BlackRock Series Fund, Inc.

BlackRock Balanced Capital Portfolio

BlackRock Global Allocation Portfolio

BlackRock Series Fund II, Inc.

BlackRock High Yield Portfolio

BlackRock U.S. Government Bond Portfolio

BlackRock Series, Inc.

BlackRock International Fund

BlackRock Strategic Global Bond Fund, Inc.

BlackRock Variable Series Funds, Inc.

BlackRock Basic Value V.I. Fund

BlackRock Equity Dividend V.I. Fund

BlackRock Global Allocation V.I. Fund

BlackRock International Index V.I. Fund

BlackRock International V.I. Fund

BlackRock Large Cap Focus Growth V.I. Fund

BlackRock Managed Volatility V.I. Fund

BlackRock Variable Series Funds II, Inc.

BlackRock High Yield V.I. Fund

BlackRock Total Return V.I. Fund

BlackRock U.S. Government Bond V.I. Fund

Managed Account Series

BlackRock GA Disciplined Volatility Equity Fund

BlackRock GA Dynamic Equity Fund

(each, a “Fund” and collectively, the “Funds”)

Supplement dated June 8, 2020 to the Summary Prospectus(es), as applicable, and Prospectus(es) of each Fund

Effective immediately, the Summary Prospectus(es), as applicable, and Prospectus(es) of each Fund are amended as follows:

The following is added to the risk factor entitled “Foreign Securities Risk” in the section of each Fund’s Summary Prospectus(es), as applicable, entitled “Key Facts About [the Fund] — Principal Risks of Investing in the Fund” or “Key Facts About [the Fund] — Principal Risks of Investing in the Fund, the Underlying Funds and/or the ETFs” and the section of each Fund’s Prospectus(es) entitled “Fund Overview — Key Facts About [the Fund] — Principal Risks of Investing in the Fund” or “Fund Overview — Key Facts About [the Fund] — Principal Risks of Investing in the Fund, the Underlying Funds and/or the ETFs,” as applicable:

• The Fund’s claims to recover foreign withholding taxes may not be successful, and if the likelihood of recovery of foreign withholding taxes materially decreases, due to, for example, a change in tax regulation or approach in the foreign country, accruals in the Fund’s net asset value for such refunds may be written down partially or in full, which will adversely affect the Fund’s net asset value.