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 US, Puerto Rico, Virgin Islands, and certain Pacific Islands.
Unit of Observation: 
Personally Identifiable Information Available for Linking: 
All United States, United States
Years Available: 

1978 – present (except 1984 and 1990)

Free or Paid: 
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 foud 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 Tom Lorge ([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.




To initiate the linking process, if National Provider Identifier (NPI) and/or Unique Physician Identification Number (UPIN) are encrypted (e.g., they were encrypted by CMS or Surveillance, Epidemiology and End Results (SEER)), they 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.

Identifiers Available for Linking
  • Address
  • First and last name
  • Medical Education (ME) Number
  • 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

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
January 2019