<SUBMISSION>
<ACCESSION-NUMBER>0001047469-04-034975
<TYPE>424B3
<PUBLIC-DOCUMENT-COUNT>1
<FILING-DATE>20041122
<DATE-OF-FILING-DATE-CHANGE>20041122
<FILER>
<COMPANY-DATA>
<CONFORMED-NAME>AVALONBAY COMMUNITIES INC
<CIK>0000915912
<ASSIGNED-SIC>6798
<IRS-NUMBER>770404318
<STATE-OF-INCORPORATION>MD
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<FILING-VALUES>
<FORM-TYPE>424B3
<ACT>33
<FILE-NUMBER>333-62855
<FILM-NUMBER>041161461
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>2900 EISENHOWER AVENUE
<STREET2>SUITE 300
<CITY>ALEXANDRIA
<STATE>VA
<ZIP>22314
<PHONE>7033296300
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>2900 EISENHOWER AVENUE
<STREET2>STE 300
<CITY>ALEXANDRIA
<STATE>VA
<ZIP>22314
</MAIL-ADDRESS>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>AVALON BAY COMMUNITIES INC
<DATE-CHANGED>19980618
</FORMER-COMPANY>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>BAY APARTMENT COMMUNITIES INC
<DATE-CHANGED>19931208
</FORMER-COMPANY>
</FILER>
<DOCUMENT>
<TYPE>424B3
<SEQUENCE>1
<FILENAME>a2147153z424b3.htm
<DESCRIPTION>424B3
<TEXT>
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<FONT SIZE=3 ><A HREF="#04WDC1918_1">QuickLinks</A></FONT>
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<P ALIGN="RIGHT"><FONT SIZE=2><B>Filed Pursuant to Rule&nbsp;424(b)(3)<BR>
Registration No.&nbsp;333-62855  </B></FONT></P>

<P ALIGN="CENTER"><FONT SIZE=2><B> <A NAME="ma1918_prospectus_supplement_to_prosp__pro03973"> </A>
<A NAME="toc_ma1918_1"> </A>
<BR>    Prospectus Supplement to Prospectus dated October&nbsp;29, 1998    <BR>    <BR>    AvalonBay Communities,&nbsp;Inc.    <BR>    <BR>    482,313 Shares of Common Stock    <BR>    </B></FONT></P>

<P><FONT SIZE=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;This Prospectus Supplement supplements the information we provided in our October&nbsp;29, 1998 Prospectus relating to 482,313 shares of our Common Stock that
we have issued or may issue in the future when we redeem limited partnership ownership interests in Avalon DownREIT V, L.P. This Prospectus Supplement is not complete without the Prospectus, and we
have not authorized anyone to deliver or use this Prospectus Supplement without the Prospectus. </FONT></P>


<P><FONT SIZE=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;In
this Prospectus Supplement, we use some capitalized terms that we defined in the Prospectus. You should read the Prospectus to understand those terms. Unless we indicate otherwise,
the information in this Prospectus Supplement is as of November&nbsp;22, 2004. </FONT></P>

<P><FONT SIZE=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;As
a result of the pledge of Units owned by a Selling Stockholders identified in the prospectus dated October&nbsp;29, 1998, we are providing this Prospectus Supplement to update the
table under the caption "Selling Stockholders." Footnote (14)&nbsp;of the table contained in such prospectus, referencing David J. Hubbard, is hereby deleted in its entirety and replaced with the
following: </FONT></P>

<UL>
<UL>

<P><FONT SIZE=2>Represents
units owned by the David J. Hubbard Trust dated August&nbsp;27, 2001, of which Mr.&nbsp;Hubbard is the Trustee. Mr.&nbsp;Hubbard may be deemed the beneficial owner of the shares of
common stock acquired upon redemption of such units pursuant to Rule&nbsp;13d-3 of the Securities Exchange Act of 1934. Pursuant to a ISDA Master Agreement and Credit Support Annex (the
"ISDA Agreement") by and between David J. Hubbard, as Trustee of the David J. Hubbard Trust dated August&nbsp;27, 2001 ("Hubbard") and Merrill Lynch, Pierce, Fenner&nbsp;&amp; Smith Incorporated
("MLPF&amp;S"), 38,634.74 Limited Partnership Units and underlying shares of Common Stock that are subject to this prospectus have been pledged by Hubbard to MLPF&amp;S as security for a loan or other
extension of credit to Hubbard. Upon a default under the ISDA Agreement, MLPF&amp;S, its parent, Merrill Lynch&nbsp;&amp; Co.&nbsp;Inc. or any subsidiary thereof, may be a selling holder hereunder and
upon the exchange of such Limited Partnership Units, may sell the applicable shares of Common Stock offered by this prospectus. In connection with the foregoing, Hubbard may enter into derivative
transactions with MLPF&amp;S and in
connection with those derivative transactions, MLPF&amp;S may sell shares covered by this prospectus, including in short sale transactions. If so, MLPF&amp;S may use shares pledged by or borrowed from Hubbard
or others to settle those sales or to close out any related open borrowings of shares, and may use shares received from Hubbard in settlement of such derivatives to close out any related open
borrowings of stock. Hubbard may enter into option or other transactions with MLPF&amp;S that involve the delivery of the shares offered hereby to MLPF&amp;S, who may then resell or otherwise transfer those
shares using this prospectus. MLPF&amp;S or other third party in such derivative or other transactions may be an underwriter. </FONT></P>

</UL>
</UL>

<P><FONT SIZE=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The
date of this Prospectus Supplement is November&nbsp;22, 2004. </FONT></P>

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<FONT SIZE=2><A HREF="#toc_ma1918_1">Prospectus Supplement to Prospectus dated October 29, 1998 AvalonBay Communities, Inc. 482,313 Shares of Common Stock</A></FONT><BR>
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