EXHIBIT A
to
Shareholder Services Agreement
Amended May 1, 2005
Fund/Share Class Annual Percentage Rate
Vanguard Institutional Index Fund
o Institutional Shares - for Basic Services & Special Services 0.03%
o Institutional Plus Shares - for Basic Services, only 0.005%
Vanguard Institutional Total Bond Market Index Fund
o Institutional Shares - for Basic Services & Special Services 0.03%
Vanguard Institutional Total Stock Market Index Fund
o Institutional Shares - for Basic Services & Special Services 0.025%
o Institutional Plus Shares - for Basic Services, only 0.005%
ACKNOWLEDGED AND AGREED AS OF MAY 1, 2005:
ATTEST: VANGUARD INSTITUTIONAL INDEX FUNDS
By_________________ By_/s/___R. ▇▇▇▇▇▇▇ ▇▇▇▇▇▇_________________
Secretary
ATTEST: THE VANGUARD GROUP, INC.
By_________________ By__/s/____▇▇▇▇ ▇ ▇▇▇▇▇▇▇___________________
Chairman and Chief Executive Officer
