Claim Coded with both ICD-9 & ICD-10

Hello,
In the Article - "ICD-10: The Wave (or Tsunami) of the Future", there is a statement - "In addition, claims submitted with a mix of ICD-9 and ICD-10 codes will be denied."

Can you please let me know if this is a CMS mandate or just best practice to create a claim with only one of the code sets?
If its a CMS mandate, then can you please provide the reference link to the CMS website where CMS has stated such rule.

Thanks,
Hershmit

re: Claim Coded with both ICD-9 & ICD-10

Claims with date of service October 1, 2013 and after, must have ICD-10 codes. Claims with date of service before Oct 1, 2013 will have ICD-10 codes.
http://www.cms.gov/ICD10/

re: Claim Coded with both ICD-9 & ICD-10

Correction:
Before Oct 1, 2013 will use ICD-9 diagnosis codes (Not I-10)

re: Claim Coded with both ICD-9 & ICD-10

Is this a possible scenario?
In the case of an outpatient visit (837P) that has left open-ended (expected multiple
visits because of chemo or dialysis) which ranges from September 2013 to October 2013.

In such cases what should be expected? Will the providers be splitting the claim for the services performed up until Sept 30 and then start with a new claim for DOS>=Oct 1st ?

re: Claim Coded with both ICD-9 & ICD-10

CMS has indicated they want only one code set per claim i.e., all ICD-9 or all ICD-10.

re: Claim Coded with both ICD-9 & ICD-10

Sorry to bring this up again. But can you please provide the exact reference on the CMS website, where CMS has stated such thing? I am not able to find it.

re: Claim Coded with both ICD-9 & ICD-10

There was no response to the question regarding as to where on the CMS website that was posted.

re: Claim Coded with both ICD-9 & ICD-10

The Centers for Medicare & Medicaid Services (CMS) Web site www.cms.gov/ICD10 has of?cial CMS resources to help you prepare for Version 5010 and ICD-10.