Form: SC 13G/A

Schedule filed to report acquisition of beneficial ownership of 5% or more of a class of equity securities by passive investors and certain institutions

February 15, 2006

SC 13G/A: Schedule filed to report acquisition of beneficial ownership of 5% or more of a class of equity securities by passive investors and certain institutions

Published on February 15, 2006

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G


(Rule 13d-102)


INFORMATION STATEMENT PURSUANT TO RULES 13d-1 AND 13d-2


Under the Securities Exchange Act of 1934
(Amendment No. 5)

AVALONBAY COMMUNITIES INC
-----------------------------------------------------
(Name of Issuer)

Common Stock
-----------------------------------------------------
(Title of Class of Securities)

053484101
-----------------------------------------------------
(CUSIP Number)

December 31, 2005
-----------------------------------------------------
(Date Of Event which Requires Filing of this Statement)



Check the following box if a fee is being paid with this statement [].

- ----------
*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).

CUSIP No. 053484101 13G Page 2 of 8 Pages
- --------------------------------------------------------------------------------
1. NAME OF REPORTING PERSON(S)
S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON(S)
Morgan Stanley
IRS # 36-314-5972
- --------------------------------------------------------------------------------
2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*

- --------------------------------------------------------------------------------
3. SEC USE ONLY

- --------------------------------------------------------------------------------
4. CITIZENSHIP OR PLACE OF ORGANIZATION
The state of organization is Delaware.
- --------------------------------------------------------------------------------
NUMBER OF 5. SOLE VOTING POWER
SHARES 3,701,139
BENEFICIALLY --------------------------------------------------------------
OWNED BY 6. SHARED VOTING POWER
EACH 1,986
REPORTING --------------------------------------------------------------
PERSON 7. SOLE DISPOSITIVE POWER
WITH 3,701,139
--------------------------------------------------------------
8. SHARED DISPOSITIVE POWER
1,986
- --------------------------------------------------------------------------------
9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
4,968,367
- --------------------------------------------------------------------------------
10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

- --------------------------------------------------------------------------------
11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
6.8%
- --------------------------------------------------------------------------------
12. TYPE OF REPORTING PERSON*
IA, CO, HC
- --------------------------------------------------------------------------------
*SEE INSTRUCTIONS BEFORE FILLING OUT!

CUSIP No. 053484101 13G Page 3 of 8 Pages
- --------------------------------------------------------------------------------
1. NAME OF REPORTING PERSON(S)
S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON(S)

Morgan Stanley Investment Management Inc.
IRS # 13-304-0307
- --------------------------------------------------------------------------------
2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*

- --------------------------------------------------------------------------------
3. SEC USE ONLY

- --------------------------------------------------------------------------------
4. CITIZENSHIP OR PLACE OF ORGANIZATION
The state of organization is Delaware.
- --------------------------------------------------------------------------------
NUMBER OF 5. SOLE VOTING POWER
SHARES 3,127,362
BENEFICIALLY --------------------------------------------------------------
OWNED BY 6. SHARED VOTING POWER
EACH 0
REPORTING --------------------------------------------------------------
PERSON 7. SOLE DISPOSITIVE POWER
WITH 3,127,362
--------------------------------------------------------------
8. SHARED DISPOSITIVE POWER
0
- --------------------------------------------------------------------------------
9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
4,274,844
- --------------------------------------------------------------------------------
10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

- --------------------------------------------------------------------------------
11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
5.8%
- --------------------------------------------------------------------------------
12. TYPE OF REPORTING PERSON*
IA, CO
- --------------------------------------------------------------------------------
*SEE INSTRUCTIONS BEFORE FILLING OUT!


CUSIP No. 053484101 13G Page 4 of 8 Pages

Item 1. (a) Name of Issuer:
AVALONBAY COMMUNITIES INC
--------------------------------------------------------------
(b) Address of Issuer's Principal Executive Offices:
2900 EISENHOWER AVENUE
SUITE 300
ALEXANDRIA, VA 22314
--------------------------------------------------------------
Item 2. (a) Name of Person Filing:
(a) Morgan Stanley
(b) Morgan Stanley Investment Management Inc.
--------------------------------------------------------------
(b) Address of Principal Business Office, or if None, Residence:
(a) 1585 Broadway
New York, NY 10036

(b) 1221 Avenue of the Americas
New York, NY 10020
--------------------------------------------------------------
(c) Citizenship:
Incorporated by reference to Item 4 of the
cover page pertaining to each reporting person.
--------------------------------------------------------------
(d) Title of Class of Securities:
Common Stock
--------------------------------------------------------------
(e) CUSIP Number:
053484101
--------------------------------------------------------------

Item 3. (a) Morgan Stanley is a parent holding company.

(b) Morgan Stanley Investment Management Inc. is an Investment
Adviser registered under Section 203 of the Investment
Advisers Act of 1940.



CUSIP No. 053484101 13-G Page 5 of 8 Pages


Item 4. Ownership.

Incorporated by reference to Items (5) - (9) and (11) of the
cover page.

(a) Morgan Stanley is filing solely in its capacity as the
parent company of, and indirect beneficial owner of
securities held by, one of its business units.

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

Inapplicable

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

Accounts managed on a discretionary basis by Morgan Stanley
Investment Management Inc., a wholly owned subsidiary of Morgan
Stanley, are known to have the right to receive or the power to
direct the receipt of dividends from, or the proceeds from, the
sale of such securities. No such account holds more than 5
percent of the class.

See item 4 (a)

Item 7. Identification and Classification of the Subsidiary which Acquired
the Security Being Reported on By the Parent Holding Company.

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

Item 9. Notice of Dissolution of Group.

Item 10. Certification.

By signing below I certify that, to the best of my knowledge and
belief, the securities referred to above were acquired in the
ordinary course of business and were not acquired for the purpose
of and do not have the effect of changing or influencing the
control of the issuer of such securities and were not acquired in
connection with or as a participant in any transaction having
such purpose or effect.

CUSIP No. 053484101 13-G Page 6 of 8 Pages


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.


Date: February 15, 2006


Signature: /s/ Dennine Bullard
-----------------------------------------------------------------

Name/Title Dennine Bullard/Executive Director, Morgan Stanley & Co.
Incorporated
-----------------------------------------------------------------
MORGAN STANLEY


Date: February 15, 2006


Signature: /s/ Carsten Otto
-----------------------------------------------------------------

Name/Title Carsten Otto/Managing Director, Morgan Stanley Investment
Management Inc.
-----------------------------------------------------------------
MORGAN STANLEY INVESTMENT MANAGEMENT INC.




INDEX TO EXHIBITS PAGE
----------------- ----

EXHIBIT 1 Agreement to make a joint filing 7

EXHIBIT 2 Secretary's Certificate Authorizing Dennine Bullard 8
to Sign on behalf of Morgan Stanley


* Attention. Intentional misstatements or omissions of fact constitute federal
criminal violations (see 18 U.S.C. 1001).



EX-99
JOINT FILING AGREEMENT


CUSIP No. 053484101 13-G Page 7 of 8 Pages


EXHIBIT 1 TO SCHEDULE 13G
---------------------------------------------------


FEBRUARY 15, 2006
---------------------------------------------------


MORGAN STANLEY and MORGAN STANLEY INVESTMENT MANAGEMENT INC.,

hereby agree that, unless differentiated, this Schedule 13G

is filed on behalf of each of the parties.


MORGAN STANLEY

BY: /s/ Dennine Bullard
--------------------------------------------------------------------
Dennine Bullard/Executive Director, Morgan Stanley & Co. Incorporated

MORGAN STANLEY INVESTMENT MANAGEMENT INC.

BY: /s/ Carsten Otto
--------------------------------------------------------------------
Carsten Otto/Managing Director, Morgan Stanley Investment
Management Inc.


* Attention. Intentional misstatements or omissions of fact constitute federal
criminal violations (see 18 U.S.C. 1001).

EX-99.b
SECRETARY'S CERTIFICATE


CUSIP No. 053484101 13-G Page 8 of 8 Pages

EXHIBIT 2
------------------

MORGAN STANLEY

SECRETARY'S CERTIFICATE


I, Charlene R. Herzer, a duly elected and acting Assistant Secretary
of Morgan Stanley, a corporation organized and existing under the
laws of the State of Delaware (the "Corporation"), certify as
follows:


(1) Donald G. Kempf, Jr. served as the duly elected Executive
Vice President, Chief Legal Officer and Secretary of the
Corporation from December 1, 1999 to August 26, 2005;

(2) Pursuant to Section 7.01 of the Bylaws of the Corporation
and resolutions approved by the Board of Directors of the
Corporation on September 25, 1998, the Chief Legal Officer
is authorized to enter into agreements and other instruments
on behalf of the Corporation and may delegate such powers
to others under his jurisdiction; and

(3) Donald G. Kempf signed a Delegation of Authority as of
February 23, 2000, which authorized Dennine Bullard to
sign reports to be filed under Section 13 and 16 of the
Securities Exchange Act of 1934 on behalf of the
Corporation. Such authorization is in full force and
effect as of this date.

IN WITNESS WHEREOF, I have hereunto set my name and affixed the seal
of the Corporation as of the 23rd day of January, 2006.

______________________________
Charlene R. Herzer
Assistant Secretary