Provider Notice issued 04/23/2026

Reminder Regarding Receipt of Second 999 Implementation Acknowledgement

The EDI 999 transaction set is an Implementation Acknowledgement document used in 837 electronic healthcare transactions to confirm that claims were received.  This notice seeks to remind providers that it is the provider’s responsibility to verify all Fee-For-Service (FFS) claim(s) were received by the Department, including claims submitted on a provider’s behalf via billing agents or clearinghouses. 

The Department rejects 837 electronic claim submissions at the ST/SE level.  If a second 999 Implementation Acknowledgement is sent by the Department, the second 999 will indicate which ST/SE level within the file has rejected, and all claims or transactions within those particular ST/SE levels will not be accepted into the claims processing system for adjudication. There is no other notification regarding file failure other than a second 999. Providers and billing agents should pay careful attention to the possibility of receiving a second 999 transaction. Should a second 999 be received, providers or the billing agent(s)/clearinghouses submitting claims on their behalf must correct any errors and resubmit prior to the timely filing deadline applicable to the claims involved.   

Providers should expect to receive remittance advice and/or be able to check claim status soon after file submission. Per the Chapter 100 Handbook for Providers of Medical Services General Policy and Procedures, providers should resubmit claims if their claims fail to appear in the MEDI system within 30 days following FFS claim(s) submission to the Department.

It is the provider’s responsibility to ensure claims are received by HFS within the timely filing limits. Claims that are not submitted and received in compliance with the time limits for claim submittal will not be eligible for payment by the Department and the State shall have no liability for payment. Refer to 89 Ill. Adm. Code 140.20 for additional information on time limits for filing a claim. Timely filing overrides will not be granted by the Department for anything not listed as an exception to the timely filing policy per the SMART Act or Administrative Rule.

Questions regarding this notice may be directed to the Bureau of Professional and Ancillary Services at 877-782-5565.

Laura Phelan, Administrator
Division of Medical Programs