Practice Affiliations Data Dictionary
Last updated: May 6, 2026
Output Column | Description | Methodology |
Payer | Full payer name, e.g. “Blue Cross Blue Shield of Alabama” | |
NetworkName | Full network name where delineated by payer MRF index, e.g. “Blue Choice Platinum for Business - PPO” | We keep the plan_name indicated in the table of contents file if fully defined; if not or ambiguous we may use web searches or other sources to identify the plan name. |
NetworkRegion | The state abbreviation (e.g. "TX", "CA"), or USA for national | If the plan name in the table of contents or the plan_id includes a HIOS state code, this is used to determine NetworkRegion. If ambiguous, we may use web searches or other sources to identify the network region. |
NetworkYearMonth | The yyyymm year month of this MRF posting | We use the month and year of the _index_ file, if unambiguous. If not present or obvious, we will use the month and year indicated in the in-network file name, and if that is not present or obvious, we will match it to the year and month of access. |
EntityGroupName | Group name assigned by Serif Health based on EIN for the record | Normalized group names based on similar entity names |
EIN | Will be a 9 digit un-hyphenated EIN or a 10 digit NPI number, each payer may use either format. EINs can be zero-led so this must be a text field. | |
EntityName | The name of the organization, practice group, or provider that was resolved. | Name tables come from NPPES as well as proprietary and public sources like EDGAR filings, IRS notices, legal filings, etc. |
NPI | 10 digit NPI | |
FirstName | First name of NPI | Derived from NPPES database |
MiddleName | Middle name of NPI | Derived from NPPES database |
LastName | Last name of NPI | Derived from NPPES database |
Credential | Credential of NPI | Derived from NPPES database |
Address1 | Address where the NPI is registered | Derived from NPPES database |
Address2 | Extended / additional address where the NPI is registered | Derived from NPPES database |
City | City where the NPI is registered | Derived from NPPES database |
County | County where the NPI is registered | Derived from NPPES database |
State | State where the NPI is registered | Derived from NPPES database |
Zip | 5-digit zip code where the NPI is registered | Derived from NPPES database |
PrimaryTaxonomy | An NUCC primary taxonomy code such as "207X00000X". | Derived from NPPES database |
TaxonomyGroup | Taxonomy group based on PrimaryTaxonomy | Derived from NPPES database |
IsType1 | Boolean field indicating whether NPI is Type1 or Type2 | Read here for more details on the difference between Type1 and Type2 NPIs: https://help.serifhealth.com/article/23-guide-to-provider-search |