Here is a timeline of important dates relating to HIPAA Compliance:
(All compliance deadlines are in RED)

April 21, 2006 SECURITY - Compliance deadline
(small health plans)
 
August 1, 2005 EMPLOYER IDENTIFIER STANDARD -
Compliance deadline
(small health plans)
 
April 21, 2005 SECURITY - Compliance deadline
(for all covered entities except small health plans)
 
July 30, 2004 EMPLOYER IDENTIFIER STANDARD -
Compliance deadline
(for all covered entities except small health plans)
 
April 14, 2004 PRIVACY - Compliance deadline
(small health plans)
 
October 16, 2003 Transactions & Code Sets - Compliance deadline
(all covered entities who filed for an extension and
small health plans)
 
April 16, 2003 Transactions & Code Sets - deadline for starting
software and systems testing
 
April 14, 2003 PRIVACY - Compliance deadline
(for all covered entities except small health plans)
 
Spring 2003 HEALTH PLAN (Payer) IDENTIFIER NPRM - expected date of publication
 
Early 2003 PROVIDER IDENTIFIER FINAL RULE - expected date of publication
 
February 13, 2003 SECURITY FINAL RULE - date of publication
 
February 13, 2003 ADDENDUM to TRANSACTIONS & CODE SETS FINAL RULE -  date of publication
 
October 16, 2002 Transaction and Code Sets - deadline for compliance or request for one year extension
 
May 31, 2002 Employer Identifier Standard Final Rule Published
 
December 28, 2000 Privacy Final Rule Published
 
August  17, 2000 Transaction and Code Sets Final Rule Published
 
February 21, 2000 Deadline for DHHS Secretary to publish privacy standards for individually identifiable health information.
 
February 17, 2000 Extended deadline for comment period on Privacy Standards for Individually Identifiable Health Information.
 
January 3, 2000 60 day comment period on Privacy Standards for Individually Identifiable Health Information ends.
 
November 3, 1999 Privacy Standards for Individually Identifiable Health Information is published in Federal Register
 
October 29, 1999 Clinton Administration Announces Proposed Rules -- Privacy Standards for Individually Identifiable Health Information.
 
August 21, 1999 Deadline for Congress to enact legislation governing the privacy of individually identifiable health information standards. Because Congress failed to meet the deadline, HIPAA requires the Secretary of Health and Human Services to promulgate such standards by regulation.
 
November 3, 1999 Privacy NPRM published
 
August 12, 1998 Security NPRM published.
 
June 16, 1998 Employer Identifier NRPM published
 
May 7, 1998 National Provider Identifier NPRM published
Transactions and Code Sets NPRM published
 

Please note:

The NPRM's (Notice of Proposed Rule Making) below have been published and are still awaiting dates for expected final rule publication and/or expected date of compliance:

National Provider Identifier

The following NPRM's are still in development and have no expected date for publication, final rule publication and compliance:

National Health Plan Identifier
Claims Attachments
Enforcement
National Individual Identifier (on hold)