Hi Somaiya,
Thank you for your questions related to linking EOB and CCLFA records on natural keys.
These facility and billing provider numbers have a different role in the processing of a claim. According to the CCLF Information packet, PRVDR_OSCAR_NUM is the facility's CCN, formerly known as the OSCAR Number, which is the identifier used by Medicare/Medicaid for certification of the type of services a facility/provider can provide in the claim. This is different from the standard NPI (National Provider Identifier), which is a unique 10 digit number that identifies providers in claims, referrals, etc.
The billing versions of these facility and provider numbers and fields are often the same as the facilities or providers that are providing the services in the claim. However, there are cases where the provider who actually submits the claim (the "billing provider") could be different from the facility where services are provided or the location of care, like if a provider associated with one CCN has the ability to bill from different locations (like at a hospital compared to a clinic) or for different services under separate billing provider numbers. Although the billing provider could act as a proxy where the facility number is not available, it would be more accurate to use the natural keys outlined in the information packet to combine the EOB and CCLFA records.
Hope this helps!
The BCDA Team