I have never heard any such thing - this sounds like complete nonsense. Whoever told you this is clearly not familiar with the way insurance companies operate. You're correct - insurance companies track their patients' deductibles and out-of-pockets based on claims processed. Providers can have no way of knowing how much of a deductible a patient has met since they do not have access to other practices' or facilities' financial records to be able to view what a patient has or has not paid. You're also correct that meeting the deductible occurs when the patient obligation is incurred, not when it is paid by the patient to the provider.
There is absolutely no reason to submit this information with your claims. This information won't be used by the insurance company and it would be a complete waste of your time to do this. I don't think you're going to find documentation to support that you don't have to do this - after all, documentation tells you what you are required to do, not what you are not required to do. Why would anyone submit extra information to an insurance company that they haven't even asked for? Rather, whoever is telling you that you need to do this is the one who should be giving you the written evidence that the insurance company actually requires this. Although I'm not sure it really applies to this particular situation, you may wish to cite the HIPAA 'minimum necessary' rule to rebut this - that you are required to only submit the minimum necessary amount of information in order to complete the transaction. To protect your patients' privacy, you shouldn't be submitting extra information that the insurance has not indicated that they need in order to process their claims.on'te