Fact Sheets

Additional Medicaid and CHIP T-MSIS Analytic Files Data Release


Given the primary role that Medicaid and the Children’s Health Insurance Program (CHIP) serve as the backbone of our nation’s safety net health care system, the Centers for Medicare & Medicaid Services (CMS) has made significant investments in these programs’ information technology and data analytic infrastructure. These investments are designed to improve access to high-quality, timely Medicaid and CHIP data to ensure robust monitoring and oversight of these vital programs that provide healthcare coverage to more than 73 million Americans. The Transformed Medicaid Statistical Information System (T-MSIS) initiative transitioned state reporting from the legacy Medicaid Statistical Information System (MSIS) to a timelier and expanded data set using a modernized technology platform to collect enhanced Medicaid and CHIP data from states.

Because of the size and complexity of T-MSIS files and the frequency of updates, these raw data files are challenging to use directly for analytic purposes. Therefore, CMS created a series of data sets optimized for analytics, known as the T-MSIS Analytic Files (TAF) consisting of research identifiable files (RIFs).  TAF RIFs contain beneficiary-level data that are available with an approved Data Use Agreement. These research files are used by CMS, oversight entities and researchers to answer key questions about the Medicaid and CHIP programs.

In November 2019, CMS released TAF RIFs for calendar years 2014, 2015, and 2016. Today’s release includes data from calendar years 2017 and 2018, which is a significant step forward in the timeliness of available data. In addition to providing access to more timely data, the overall quality of the data has improved notably compared to the initial data released last November.

In July, CMS launched the Data Quality (DQ) Atlas tool, which is an interactive, web-based tool to help policymakers, analysts, researchers, and other stakeholders explore the data quality of T-MSIS research data.  With today’s release, the DQ Atlas tool will include data files from calendar years 2017 and 2018. 

What is included in this release and who will use it?

CMS is releasing additional years of research-ready T-MSIS data files and products.  As previously mentioned, this release includes calendar year 2017 and 2018 TAF RIFs along with the corresponding TAF user support products.  User support products include DQ Atlas, which allows the public to review the quality and usability of the T-MSIS research-ready files for all calendar years of published T-MSIS data, as well as TAF Technical Guidance documents. CMS, oversight entities, and researchers will use the TAF RIFs and supporting documentation for program monitoring, oversight, model evaluations, and answering key questions about Medicaid and CHIP.  Releasing more timely Medicaid and CHIP data for program oversight is a significant milestone for CMS.


The TAF RIFs include annual files that contain demographic and eligibility information for all Medicaid and CHIP eligible beneficiaries as well as claims files that contain service use and payment records. Data shared with researchers will not include beneficiary names, street addresses, or phone numbers, to protect beneficiary privacy, and proprietary managed care payment information will be redacted for external researchers. A total of five file types are being released for calendar years 2017 and 2018 at this time:

  • Annual Demographics and Eligibility (DE) File
  • Inpatient Hospital (IP) Claims File
  • Long-Term Care (LT) Claims File
  • Pharmacy (RX) Claims File
  • Other Services (OT) Claims File

CMS is continuously working with each state to improve the quality and completeness of T-MSIS data. The quality of the data has improved and continues to improve.  To balance providing timely data with accurate data, CMS plans to rerun the 2017 and 2018 TAF RIFs in Winter 2021 to reflect improved data from states for that reporting period.  The updated 2017 and 2018 TAF RIFs are expected to be released later in 2021.

TAF User Support Products

CMS created several resources to support researchers in their use of the TAF RIF, including technical guidance and updated data quality information in DQ Atlas. These products assist the TAF user community in assessing the accuracy, reliability and usability of the files.

  • TAF Technical Guidance Documents provide detailed instructions on how to use the data for analysis.
  • DQ Atlas tool gives researchers the ability to conduct insightful, methodologically sound analyses of key Medicaid and CHIP topics such as enrollment, claims, expenditures, and service use by making available information to determine if the data can meet their analytic needs.
  • Introductory materials are also available to help end users of the data get started quickly, which include:
    • an introduction to TAF presentation
    • a crosswalk that provides TAF analogs to Medicaid Analytic eXtract (MAX) user support materials
    • TAF availability chart outlining when states are first included in TAF
  • DQ Atlas can be found here on All additional supporting technical documentation can also be found through

Has T-MSIS data quality improved in recent years?

Over the last several years, CMS has been working with each state to improve the quality and completeness of its T-MSIS submissions and will continue to do so. CMS has identified 32 T-MSIS Priority Items (TPIs) related to T-MSIS data quality and states have made significant progress in addressing these items. Information on the number of open TPIs per state for the first 23 TPIs can be found in the state maps here. Moving forward, CMS will continue to work with the states to improve the quality of their data.

State data quality has improved substantially in recent submissions. As DQ Atlas demonstrates, state data quality in 2017 is similar to 2018, and both years are notably better than the previously released 2016 data. The vast majority of states and territories (44 in total) had an equal or higher proportion of DQ Assessments of “low concern” in 2017 compared to 2016. Arkansas and Puerto Rico, which CMS previously excluded from the previous TAF RIFs due to significant data quality issues, submitted greatly improved data now available in the 2017 and 2018 TAF RIFs.  Mississippi has also implemented large improvements in data quality between 2016 and 2017. Additionally, data from the U.S. Virgin Islands and accompanying data quality information are now available for the first time.

How do researchers and external partners obtain access to TAF RIF?

All external researchers who want to obtain access to the TAF RIFs should contact the CMS Research Data Assistance Center (ResDAC). ResDAC staff will work with the researcher to identify the CMS data files available to conduct his/her study and assist with completing the forms needed for the request package.  Researchers who are approved for access to the TAF will be required to sign a CMS data use agreement that contains strict beneficiary privacy and data security requirements.  To learn more, visit the ResDAC website at:  

What’s next?

CMS plans to rerun the 2014-2016 TAF RIFs to reflect improved data quality and expects to release updated data in October 2020. Next, CMS expects to release preliminary 2019 TAF RIFs in December 2020, with the final 2019 TAF RIFs released in 2021. Lastly, CMS plans to rerun the 2017 and 2018 TAF RIFs in 2021 to reflect improved state data quality.

CMS’s release of the 2017 and 2018 TAF RIFs is a major step towards sharing timely data necessary for ensuring robust monitoring and oversight of Medicaid and CHIP. By using these Medicaid and CHIP data, CMS, states and researchers will help drive smarter spending and better health outcomes for Medicaid and CHIP beneficiaries.