ARCA BIOPHARMA, INC.
2009 REDUCTION IN FORCE
SEVERANCE BENEFIT PLAN
Adopted May 19, 2009
The ARCA Biopharma, Inc. 2009 Reduction in Force Severance Benefit Plan (the “ Plan ”) is established
effective May 19, 2009. The purpose of the Plan is to provide for the payment of severance benefits to certain
eligible employees of ARCA Biopharma, Inc. (the “ Company ”) who meet the eligibility criteria set forth in
Section 2(a) below. This Plan supersedes any severance benefit plan, policy or practice, whether formal or
informal, written or unwritten, previously announced or maintained by the Company. This Plan document also is
the Summary Plan Description for the Plan.
(a) General Rules. Subject to the requirements set forth in this Section, the Company will grant
severance benefits under the Plan to Eligible Employees.
(1) Definition of “Eligible Employee.” For purposes of this Plan, an Eligible Employee is a
full-time regular U.S. employee of the Company who is notified by the Company on May 20, 2009 in writing that
(1) his or her employment is being terminated on May 20, 2009 by the Company without cause and other than as
a result of the employee’s death or disability (such termination, a “ Qualifying Termination ”) and (2) as a
result of such termination, he or she is eligible for participation in the Plan. The determination of whether an
employee is an Eligible Employee shall be made by the Company, in its sole discretion, and such determination
shall be binding and conclusive on all persons. For purposes of this Plan, full-time employees are those regular
hire employees who are regularly scheduled to work at least thirty-two (32) hours per week. Neither temporary,
leased or seasonal employees nor intern, agency temporary employees, independent contractors, consultants or
agents under a written contract or purchase order, and persons so classified as such by the Company (whether or
not such classification is upheld on governmental, judicial or other rev