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 NCHS report:

Golden C, Driscoll AK, Simon AE, et al. Linkage of NCHS population health surveys to administrative records from Social Security Administration and Centers for Medicare & Medicaid Services. National Center for Health Statistics. Vital Health Stat 1(58). 2015. [PDF – 1.4 MB]

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 web site 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.

Data Dictionaries and Variable Crosswalk

Restricted Use Data Dictionaries:

• NCHS created variables [PDF – 69 KB]
• Person Summary (PS) File [PDF – 407 KB]
• Inpatient (IP) File [PDF – 272 KB]
• Long-term Care (LT) File [PDF – 253 KB]
• Prescription Drug (RX) File [PDF – 270 KB]
• Other Services (OT) File [PDF – 257 KB]

Variable Crosswalk:

• Restricted-Use NCHS-CMS Medicaid Files Variable Crosswalk [PDF – 403 KB]