A Prospectus filing for the Vanguard Funds tells us, "Effective immediately, Vanguard is making changes to the portfolio managers of each Fund listed in the table below as a result of an internal realignment of the municipal bond team." It says that John Grimes joins John Carbone as a Portfolio Manager for Vanguard California Municipal Money Market Fund, John Grimes joins Justin Schwartz as a Portfolio Manager for Vanguard Municipal Money Market Fund and John Carbone joins John Grimes as a Portfolio Manager for Vanguard New York Municipal Money Market Fund.