Alkermes plc. — Director's Dealing 2015

May 22, 2015

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Alkermes plc. (ALKS)
CIK: 0001520262
Period of Report: 2015-05-20

Reporting Person: FRATES JAMES M (SVP & CFO, Alkermes plc)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2015-05-20	Ordinary Shares	M	3750	—	Acquired	82399	Direct
2015-05-20	Ordinary Shares	F	1767	$62.10	Disposed	80632	Direct
2015-05-21	Ordinary Shares	M	3750	—	Acquired	84382	Direct
2015-05-21	Ordinary Shares	F	1767	$61.80	Disposed	82615	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2015-05-20	Restricted Stock Unit Award	$0	M	3750	Disposed		Ordinary Shares (3750)	Direct
2015-05-21	Restricted Stock Unit Award	$0	M	3750	Disposed		Ordinary Shares (3750)	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Ordinary Shares	4000	Indirect
Ordinary Shares	57000	Indirect

Footnotes

F1: Shares held by James M. Frates Grantor Retained Annuity Trust dated March 14, 2014 (the "GRAT"). The Reporting Person is a trustee and beneficiary of the GRAT and may be deemed to hold voting and dispositive power with regard to the reported shares held by the GRAT.

F2: This RSU award is fully vested in accordance with its terms.

F3: Shares subject to the restricted stock unit award vest in equal annual installments over a four year period, commencing on 5/21/13.