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		FOUNDED 1866

December 13, 2016

VIA EDGAR

Securities and Exchange Commission

100 F Street, NE

Washington, DC 20549

Re: BlackRock Total Stock Market Index Fund, a series of BlackRock Funds^SM

(Securities Act File No. 33-26305, Investment Company Act File No. 811-05742)

Ladies and Gentlemen:

On behalf of BlackRock Funds^SM, attached for filing are exhibits containing interactive data format risk/return summary information that mirrors the risk/return summary information in the Investor and Institutional Shares and Class K Shares Prospectuses of BlackRock Total Stock Market Index Fund (the “Fund”), each dated November 28, 2016, as filed pursuant to Rule 497(c) under the Securities Act of 1933, on December 2, 2016 (the “497 Filing”). The purpose of this filing is to submit the 497 Filing in XBRL for the Fund.

Any questions or comments on the 497 Filing should be directed to the undersigned at (212) 839-8615.

Very truly yours,

/s/ Jesse C. Kean

Jesse C. Kean

Enclosures

cc: Benjamin Archibald, Esq.

BlackRock Advisors, LLC

Sidley Austin (NY) LLP is a Delaware limited liability partnership doing business as Sidley Austin LLP and practicing in affiliation with other Sidley Austin partnerships.