X0303 4 2009-07-23 0 0001131096 ATHENAHEALTH INC ATHN 0001412135 Byers Carl B. C/O ATHENAHEALTH, INC. 311 ARSENAL STREET WATERTOWN MA 02472 0 1 0 0 SVP and CFO Common Stock 2009-07-23 4 S 0 100 38.73 D 226132 D Common Stock 2009-07-23 4 S 0 100 38.84 D 226032 D Common Stock 2009-07-23 4 S 0 100 38.02 D 225932 D Common Stock 2009-07-23 4 S 0 100 38.03 D 225832 D Common Stock 2009-07-23 4 S 0 100 38.74 D 225732 D Common Stock 2009-07-23 4 S 0 100 38.53 D 225632 D Common Stock 2009-07-23 4 S 0 100 38.48 D 225532 D Common Stock 2009-07-23 4 S 0 100 38.30 D 225432 D Common Stock 2009-07-23 4 S 0 100 38.09 D 225332 D Common Stock 2009-07-23 4 S 0 100 37.80 D 225232 D Common Stock 2009-07-23 4 S 0 100 37.90 D 225132 D Common Stock 2009-07-23 4 S 0 200 38.18 D 224932 D Common Stock 2009-07-23 4 S 0 100 38.19 D 224832 D Common Stock 2009-07-23 4 S 0 100 37.47 D 224732 D The sales reported on this Form 4 were made pursuant to a written trading plan adopted by the Reporting Person on December 16, 2008, in accordance with Rule 10b5-1. /s/ Daniel H. Orenstein Attorney-in-Fact 2009-07-24