NCHS Data Linkage

Restricted-Use NCHS-CMS Medicaid Data

NCHS survey data have been linked to the research-oriented Medicaid files known as the Medicaid Analytic eXtract (MAX) files. The MAX files include data for enrollees in Medicaid and in the Children’s Health Insurance Program (CHIP) in all 50 states and the District of Columbia.

The MAX data system consists of a person summary (PS) file and four claims files: inpatient (IP), institutional long-term care (LT), prescription drugs (RX) and other services (OT).

Detailed descriptions of each of these files can be found in the following online report:

NCHS-CMS Medicaid Matching Methodology and Analytic Considerations pdf icon[PDF – 785 KB]


Data Access

Due to confidentiality requirements, the Restricted-use NCHS-CMS Medicaid Data are accessible only through the NCHS Research Data Center (RDC). All interested researchers must submit a research proposal to the RDC. Please see the RDC website for instructions on submitting a proposal  RDC website.

NCHS has created Feasibility Study Data files to assist researchers who are considering submitting an RDC application to analyze the linked NCHS-CMS Medicaid data.

Please consult the Public-Use NCHS-CMS Medicaid Feasibility Files page for more information.


Restricted Use Data Dictionaries:


Variable List:

Page last reviewed: February 1, 2021, 03:40 PM