ResDAC is currently experiencing a high volume of requests, which may delay response and processing times. We are working to address the backlog as quickly as possible and appreciate your patience.
This variable is contained in the following files:
SAS Name
ORG_TIN
The taxpayer identification number (TIN) of the participating provider, generally an employer identification number (EIN) but may be (in the case of professionals) a Social Security number (SSN).
Source: CMS Participating Provider Pioneer ACO RIF
The legal name associated with the TIN is in the field called TIN_NAME.