X0306 4/A 2013-03-01 2013-03-08 0 0001131096 ATHENAHEALTH INC ATHN 0001204310 KAHANE STEPHEN N 311 ARSENAL STREET WATERTOWN MA 02472 0 1 0 0 President, Enterprise Services Common Stock 2013-03-01 4 A 0 7763 0.00 A 124639 D Common Stock 2013-03-01 4 F 0 189 96.09 D 124450 D Common Stock 2013-03-01 4 F 0 8167 96.09 D 116283 D Common Stock 2013-03-01 4 F 0 3192 96.09 D 111332 D Common Stock 2013-03-01 4 F 0 1475 96.09 D 109857 D Represents an award of restricted stock units pursuant to the Issuer's 2007 Stock Option and Incentive Plan, as amended and restated. The restricted stock units vest in four equal annual installments beginning on the first anniversary of the grant date. These shares were withheld to satisfy tax withholding obligations incurred upon the vesting of restricted stock units awarded to the Reporting Person on March 1, 2011. This transaction is considered an exempt sale pursuant to Rule 16b-3(e) promulgated under the Securities Exchange Act of 1934. On March 8, 2013, the Reporting Person filed a Form 4 incorrectly reporting 1,237 unearned performance-based restricted stock units when in fact 1,759 units were not earned. As a result of the error, the amount of shares beneficially owned by the Reporting Person on the Form 4 filed March 8, 2013, was incorrect. These shares were withheld to satisfy tax withholding obligations incurred upon the vesting of restricted stock units awarded to the Reporting Person on March 1, 2012. This transaction is considered an exempt sale pursuant to Rule 16b-3(e) promulgated under the Securities Exchange Act of 1934. As a result of the error described in Footnote 3, the amount of shares beneficially owned by the Reporting Person on the Form 4 filed March 8, 2013, was incorrect. /s/ Daniel H. Orenstein Attorney-in-Fact 2013-04-25