CUSIP NO. 10316T106 13 G Page 1 6 of 17

EXHIBIT A

Agreement of Joint Filing

The undersigned hereby agree that a single Schedule 13G (or any amendment thereto) relating to the Class A Common Stock of Evolent Health, Inc. shall be filed on behalf of each of the undersigned and that this Agreement shall be filed as an exhibit to such Schedule 13G.

Date: February 10, 2017

North Bridge Growth Equity I, L.P.
By:	North Bridge Growth Management, L.P., its general partner
By:	NBGE GP, LLC, its general partner
By:	North Bridge Growth Management Company, LLC, its managing manager
By:	/s/ Russell T. Pyle
Name:	Russell T. Pyle
Title:	Managing Member
North Bridge Growth Management, L.P.
By:	NBGE GP, LLC, its general partner
By:	North Bridge Growth Management
	Company, LLC, its managing manager
By:	/s/ Russell T. Pyle
Name:	Russell T. Pyle
Title:	Managing Member
NBGE GP, LLC
By:	North Bridge Growth Management
	Company, LLC, its managing manager
By:	/s/ Russell T. Pyle
Name:	Russell T. Pyle
Title:	Managing Member
North Bridge Growth Management Company, LLC
By:	/s/ Russell T. Pyle
Name:	Russell T. Pyle
Title:	Managing Member

CUSIP NO. 10316T106 13 G Page 17 of 17

DOUGLAS A. KINGSLEY

/s/ Douglas A. Kingsley

Douglas A. Kingsley

ROSHEN MENON

/s/ Roshen Menon

Roshen Menon

MICHAEL PEHL

/s/ Michael Pehl

Michael Pehl

RUSSELL T. PYLE

/s/ Russell T. Pyle

Russell T. Pyle