Our Data


This section of the CHIA website contains links to both learn about and to request Massachusetts health system data.  This data includes the Massachusetts All-Payer Claims Database (MA APCD), Acute Hospital Case Mix Databases, and Massachusetts Hospital Financial Performance information.


Massachusetts All-Payer Claims Database (MA APCD)

The MA APCD is comprised of medical, pharmacy, and dental claims, as well as information about member eligibility, benefit design, and providers from payers covering the vast majority of Massachusetts residents. The MA APCD streamlines required data submissions from payers to multiple state agencies.  It also affords a deep understanding of the Massachusetts health care system by providing access to comprehensive, and detailed data from both public and private payers. CHIA and several state agencies use the MA APCD and it is available by application to researchers and others working in the public interest.


Acute Hospital Case Mix Databases

CHIA collects patient-level data from Massachusetts acute care hospitals about each hospital inpatient stay, observation stay and emergency department visit.  These data, which have been collected by CHIA and its predecessor agencies for close to two decades, are useful for looking at long term trends in hospital utilization, readmissions, hospital market analyses and comparative charge analyses.  Widely known as “Case Mix Files,” these data are used by CHIA and several state agencies and is available by application to researchers and others working in the public interest. 


Hospital Financial Performance

CHIA's Massachusetts hospital financial performance information includes annual and quarterly reports with aggregate data and individual hospital fact sheets for Massachusetts hospitals, as well as High Public Payer Hospitals designations.


Hospital and Community Health Center Cost Report Databases

The Hospital and Community Health Center Cost Report Databases section includes an overview of the Hospital Cost Report and Community Health Center Cost Report databases.


Information About Massachusetts Hospitals

Hospitals play a central role in the Massachusetts health care system, and are critical to achieving the Commonwealth’s goals of controlling costs while maintaining or improving the quality of care delivered. CHIA monitors and provides meaningful analysis on hospitals in the Commonwealth for those seeking to improve health care quality, affordability, access and outcomes.


Long Term Care Databases

The Long Term Care Databases section contains information about nursing home and rest home cost reports; patient day and final rate listing files; and the provider history file.


Payer Data Reporting

CHIA is required under M.G.L. c. 12C to collect and report on Health Status Adjusted Total Medical Expenses (TME), Relative Prices (RP), Alternative Payment Methods (APM), and Provider Payment Methods (PPM). Regulation 957 CMR 2.00 governs the methodology and filing requirements for health care payers to calculate and report TME, RP, APM, and PPM data pursuant to M.G.L. c. 12C.

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