AVALONBAY COMMUNITIES INC — Director's Dealing 2010

Sep 7, 2010

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: AVALONBAY COMMUNITIES INC (AVB)
CIK: 0000915912
Period of Report: 2010-09-03

Reporting Person: Dunn Lili F (Senior Vice President)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2010-09-03	Common Stock, Par value $.01 per share	M	6549	$86.40	Acquired	36558.3315	Direct
2010-09-03	Common Stock, Par value $.01 per share	M	2893	$48.60	Acquired	39451.3315	Direct
2010-09-03	Common Stock, Par Value $.01 per share	S	9442	$110.1743	Disposed	30009.3315	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2010-09-03	Stock Options (Right to Buy)	$86.40	M	6549	Disposed	2018-02-11	Common Stock (6549)	Direct
2010-09-03	Stock Options (Right to Buy)	$48.60	M	2893	Disposed	2019-02-11	Common Stock (2893)	Direct

Footnotes

F1: The amount of securities owned following the reported transaction reflects direct ownership of all shares of common stock, including restricted shares.

F2: This transaction was executed in multiple trades at prices ranging from $110.03 to $110.36. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected.

F3: The options exercised were included in options granted under the issuer's stock option and incentive plan on February 11, 2008 which became exercisable in three equal installments beginning on February 11, 2009.

F4: Following the reported transaction, the reporting person held a total of 22,627 options to purchase the issuer's common stock granted on various dates and with varying exercise prices and vesting dates.

F5: The options exercised were included in options granted under the issuer's stock option and incentive plan on February 11, 2009 which became exercisable in three equal installments beginning on February 11, 2010.

F6: Following the reported transaction, the reporting person held a total of 19,734 options to purchase the issuer's common stock granted on various dates and with varying exercise prices and vesting dates.