Think that your HHH Medicare Ad-ministrative Contractor hasn't noticed that you aren't submitting claims in the 5010 format and haven't submitted a transition plan? Think again. "Submitters and trading partners still submitting 4010A1 production claims must submit a 5010 Trading Partner Testing/Transition Plan," stresses HHH MAC National Government Ser-vices in a message to providers. "These plans were due to National Government Services by February 1, 2012 for professional submitters and March 2, 2012 for institutional submitters regardless of the Health Insurance Portability and Accountability Act (HIPAA) Enforcement Guidance extension." (That extension puts off CMS's enforcement of the 5010 requirement until June 30.) "Your plans must include the reason for not migrating to the 5010 format," NGS instructs. NGS "is paying close attention to reasons causing trading partner/submitter delays and will be making contact for more information." Even if you submitted a plan, you still may not be off the hook. "If you filed a plan previously and did not meet the timeline a new plan is required," NGS directs. Bottom line: "National Government Ser-vices encourages submitters who have not transitioned to the 5010 format to complete their transition as quickly as possible to ensure timely support from National Government Services EDI support staff," the MAC says.