American Medical Association Physician Masterfile

American Medical Association (AMA) Division of Health Solutions Data Management (HSDM)

Current and historical data on all physicians in the United States.

Unit of Observation:
Personally Identifiable Information Available for Linking:
All United States, United States of America
Years Available:
1993 – 2018
Frequency of Updates:
Varies by data licensee

Virtually all Doctors of Medicine (MDs) and Doctors of Osteopathic Medicine (DOs) in the US, Puerto Rico, Virgin Islands, and certain Pacific Islands


The AMA licenses its Physician Masterfile to Database Licensees who make the database available to others. More information about licensing can be found here. The process for acquiring data may vary by licensee. The remainder of this entry describes the process for accessing and using data provided through the licensee Medical Marketing Service, Inc. (MMS). Researchers can contact Kristy Vanderplow ([email protected]) directly to request access to the data through MMS. As part of the application process, researchers must complete a data use agreement (DUA). MMS does not require IRB approval for data access.

Generally, only de-identified data are made available to researchers (i.e., data are provided without name and address). Identifiable data may be requested by detailing how the data will be used and why identifiable data are needed.

Timeline for Access


Lag Time

Lag time varies depending on the data licensee. Medical Marketing Service, Inc. advertises daily updates of their database.


Cost through MMS ranges depends on number of records, data set, and whether the data is identified. See here for a specific cost schedule. 


If National Provider Identifier (NPI) and/or Unique Physician Identification Number (UPIN) are encrypted in the external data source (e.g., data were encrypted by CMS or Surveillance, Epidemiology and End Results (SEER)) data will need to be sent to Information Management Services, Inc. (IMS) first. IMS will unencrypt the identifiers and send the file to MMS to be used for matching. The process of linking data is dependent on what is being linked. 

Identifiers Available for Linking

  • Name
  • Address
  • National Provider Identifier (NPI)
  • Unique Physician Identification Number (UPIN)
  • State License Number

Data Contents

Partial List of Variables

Physician demographic information, address, hospital affiliation, residency, medical school, specialty, historical data on location variables. Full file layouts listing all variables on the AMA Statistical Research file are available here (see the “What is available on the file” section).  

J-PAL Randomized Evaluations Using this Data Set

Doyle, Joseph J., Ewer, Steven M., and Todd H Wagner. 2010. “Returns to Physician Human Capital: Evidence from Patients Randomized to Physicians Teams.” Journal of Health Economics, 29(6): 866-882.

Last reviewed