What are the major differences between HIPAA 4010A1 and HIPAA 5010? 
There are changes across all of the transactions, some of which include
                • The ability to support new-use cases brought forward by the industry;
                • Clarification of usage to remove ambiguity;
                • Consistency across transactions;
                • Support of the NPI regulation; and
                • Removal of data content that is no longer used.
Why was it necessary to upgrade to HIPAA 5010?
The upgrade to HIPAA 5010 was important for several reasons:
                • Industry experience with the 4010A1 implementation uncovered some unanticipated issues and requirements; and
                • HIPAA 5010 will be able to accommodate the forthcoming and mandatory ICD-10-CM and ICD-10-PCS code sets, which are scheduled to be implemented on Oct. 1, 2013.
What challenges does HIPAA 5010 present to the healthcare industry?
One of the most prominent challenges is identifying the gaps between HIPAA 4010A1 and 5010. Many of the challenges facing the healthcare industry are not technical in nature but address business challenges.
Because of our commitment to guiding our clients through this transition, we will be publishing on www.hipaasimplified.com a summary document of issues and challenges that face each segment of the industry today. 
How can covered entities prepare for the transition to HIPAA 5010?
An organization should make it a priority to perform a thorough systems inventory to establish which technical and business components will be impacted by the transition to HIPAA 5010. In the analysis of business components, the organization should also review the readiness of their business partners, including clearinghouses, software vendors, etc., to confirm that they are also prepared to transition by the compliance date. 
Additionally, covered entities should perform a full internal gap analysis between HIPAA 4010A1 and HIPAA 5010. Such an analysis both focuses on a covered entity’s actual use of the content within the standard transactions and identifies the circumstances in which the changes in the standards impact the specific covered entity. This information will be vital in understanding the local impact of the transition to the organization.
Because of our commitment to guiding our clients through this transition, we will be publishing on www.hipaasimplified.com a generalized 4010A/5010 gap analysis for each HIPAA standard transaction that we support.
Are there any milestones published by HHS to help organizations meet the compliance dates?
Yes. In the preamble to the Final Rule, HHS has recommended a timeline to help the industry migrate to the new versions of the transactions:
Target Date
Jan 2009
Begin Level 1 activities (gap analysis, design, and development)
Jan 2010
Begin internal testing for HIPAA 5010 and NCPDP D.0
Dec 2010
Achieve Level 1 compliance (covered entities have completed internal testing and can send and receive compliant transactions)
Jan 2011
Begin Level 2 testing period activities (external testing with trading partners and move into production; dual 4010A/5010 processing mode)
Begin initial ICD-10 compliance activities (gap analysis, design, development, and internal testing)
Jan 1, 2012
5010/D.0 compliance date for all covered entities
Oct 1, 2013
The compliance date for ICD-10-CM and ICD-10-PCS