UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934
(AMENDMENT NO.  )*

AMAG PHARMACEUTICALS INC.
-----------------------------------------
(Name of Issuer)

COMMON
-----------------------------------------
(Title of Class of Securities)

00163U106
----------------
(CUSIP Number)

-----------------------------------------
(Date of Event Which Requires Filing of this Statement)
Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

  Rule 13d-1(b)
  Rule 13d-1(c)
  Rule 13d-1(d)

*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.
The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).

PERSONS WHO RESPOND TO THE COLLECTION OF INFORMATION CONTAINED IN THIS FORM ARE
NOT REQUIRED TO RESPOND UNLESS THE FORM DISPLAYS A CURRENTLY VALID OMB CONTROL
NUMBER.
SEC 1745 (8-07)



CUSIP No.  00163U106                 13G                   Page 2 of.5 Pages

1.  Names of Reporting Persons.
FIRST MANHATTAN CO.

2.  Check the Appropriate Box if a Member of a Group (See Instructions)
     (a) [     ]
     (b) [ X ]

3. SEC Use Only


4.  Citizenship or Place of Organization                           NEW YORK


5.  Sole Voting Power                                             1,184,815


6.  Shared Voting Power                                                   0


7.  Sole Dispositive Power                                        1,184,815


8.  Shared Dispositive Power                                              0


9.  Aggregate Amount Beneficially Owned by Each Reporting Person  1,184,815

10.  Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See
Instructions)    [  ]


11.  Percent of Class Represented by Amount in Row (9)                5.53%


12.  Type of Reporting Person (See Instructions)                 BD, IA, PN



CUSIP No. 00163U106                 13G                 Page  3 of  5  Pages

Item 1(a).  Name of Issuer:

AMAG PHARMACEUTICALS INC.

Item 1(b).  Address of Issuer's Principal Executive Offices:

100 HAYDEN AVENUE
LEXINGTON, MA  02421

Item 2(a).  Name of Person Filing:
FIRST MANHATTAN CO.

Item 2(b).  Address of Principal Business Office, or if None, Residence:

437 MADISON AVENUE
NEW YORK, NY   10022

Item 2(c).  Citizenship                                             U.S.A.

Item 2(d).  Title of Class of Securities                            COMMON

Item 2(e).  CUSIP Number:                                        00163U106

Item 3.  If this statement is filed pursuant to   240.13d-1(b) or 240.13d-2(b)
          or (c), check whether the person  filing is a:
(a)  [_]  Broker or dealer registered under  15 of the Act (15 U.S.C. 78o).
(b)  [_]  Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c).
(c)  [_]  Insurance company as defined in section 3(a)(19) of the Act
          (15 U.S.C.78c).
(d)  [_]  Investment company registered under section 8 of the Investment
          Company Act of 1940  (15U.S.C 80a-8).
(e)  [X]  An investment adviser in accordance with  240.13d-1(b)(1)(ii)(E);
(f)  [_]  An employee benefit plan or endowment fund in accordance with
          240.13d-1(b)(1)(ii)(F);
(g)  [_]  A parent holding company or control person in accordance with
          240.13d-1(b)(1)(ii)(G);
(h)  [_]  A savings associations as defined in Section 3(b) of the Federal
          Deposit Insurance Act (12  .S.C1813);
(i)  [_]  A church plan that is excluded from the definition of an investment
          company under section 3(c)(14) of the Investment Company Act of 1940
          (15 U.S.C.80a-3);
 (j) [_]  Group, in accordance with  240.13d-1(b)(1)(ii)(J).



CUSIP No. 00163U106           13G             Page  4 of  5  Pages

Item 4.  Ownership.
     Provide  the  following  information  regarding  the  aggregate  number and
percentage of the class of securities of the issuer identified in Item 1.

 (a)  Amount beneficially owned                                     1,184,815

 (b)  Percent of class:                                                 5.53%
 (c)  Number of shares as to which such person has:

       (i)    Sole power to vote or to direct the vote               1,184,815

       (ii)   Shared power to vote or to direct the vote                    0

       (iii)  Sole power to dispose or to direct the disposition of  1,184,815

       (iv)  Shared power to dispose or to direct the disposition of        0


Item 5.  Ownership of Five Percent or Less of a Class.

     If this statement is being filed to report the fact that as of the date
hereof the reporting person has ceased to be the beneficial owner of more than
five percent of the class of securities check the following:     [   ].

Item 6.  Ownership of More Than Five Percent on Behalf of Another Person.

NOT APPLICABLE

Item 7.  Identification and Classification of the Subsidiary Which Acquired the
Security Being Reported on by the Parent Holding Company or Control Person.

NOT APPLICABLE

Item 8.  Identification and Classification of Members of the Group.

NOT APPLICABLE

Item 9.  Notice of Dissolution of Group.



CUSIP No. 00163U106                 13G             Page  5 of  5 Pages


Item 10.  Certifications.
-------------------------
  (a) The following certification shall be included if the statement is filed
pursuant to  240.13d-1(b):
By signing below I certify that, to the best of my knowledge and belief, the
securities referred to above were acquired and are held in the ordinary course
of business and were not acquired and are not held for the purpose of or with
the effect of changing or influencing the control of the issuer of the
securities and were not acquired and are not held in connection with or as a
participant in any transaction having  that purpose or effect.
 (b) The following certification shall be included if the statement is filed
pursuant to  240.13d-1(c):
 By  signing  below  I certify that, to the best of my knowledge and belief, the
securities  referred  to above were acquired and are held in the ordinary course
of  business  and were not acquired and are not held  for the purpose of or with
the  effect  of  changing  or  influencing  the  control  of  the  issuer of the
securities  and  were  not  acquired and are not held in connection with or as a
participant  in  any  transaction  having  that  purpose  or  effect.

SIGNATURE
After reasonable inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this statement is true, complete and correct.

February  13,  2013
-------------------
(Date)

s/s/  Neal  K.  Stearns
-----------------------
(Signature)

Neal  K.  Stearns
Senior  Managing  Director
--------------------------
(Name/Title)

Note. Schedules filed in paper format shall include a signed original and five
copies of the schedule, including all exhibits. See Rule 13d-7 for other parties
for whom copies are to be sent.
Attention. Intentional misstatements or omissions of fact constitute federal
criminal violations (see 18 U.S.C. 1001).