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Developing Medicaid Core Set measures for States

Discover how Michigan and Virginia took different approaches to meet the federal mandate of tracking care quality for Medicaid and CHIP.

October 3. 2025 | 8-minute read

Background: CMS Core Sets

State Medicaid employees know CMS’s Child and Adult Core Sets — standardized measures tracking care quality for Medicaid and CHIP. Reporting, once voluntary, became mandatory for all states in 2024 to improve care and health outcomes.

At the 2025 State Healthcare IT Connect Summit, presenters from Optum and 2 partner states shared their experiences complying with the new CMS mandate. For each state, the different approach led to a shared outcome: enhanced cross-sector relationships that support quality improvement, care coordination and closing gaps in care. 


Experts included:

  • Yamini Raju, Data Analytics Manager, Virginia Department of Medical Assistance Services
  • Kasia Gruszka, Quality Improvement and Program Development Manager, Michigan Department of Health and Human Services
  • Meta Kreiner, Population Health Specialist, Optum State Government Solutions


CMS Adult and Child Core Sets are federally mandated health care quality measures for Medicaid and CHIP. They were established under the Social Security Act to promote national standards for reporting and improvement.

The Child Core Set launched in 2011 and was followed by the Adult Core Set in 2012. Reporting was voluntary until 2024, when it became mandatory for all Child Core Set measures and Behavioral Health measures in the Adult Core Set.

CMS updates the measures and specifications annually to reflect evolving priorities and evidence-based practices, for better relevance and impact across Medicaid and CHIP programs.

States must submit data annually. CMS publishes results for measures reported by at least 25 states that meet quality standards, helping benchmark performance and identify improvement areas.

In 2024, CMS launched a public dashboard featuring 2022 data from voluntarily reporting states. It shows national medians and state-specific metrics to guide health outcomes improvement.

Two states, two timelines

Both Michigan and Virginia started their Child Core Set reporting in 2012 and Adult Core Set reporting in 2014, and they continued voluntary reporting until 2023, the last year before mandatory reporting began.

Medicaid covers nearly 2 million Virginia residents, and the majority are enrolled in 5 managed care organizations (MCOs). Previously, MCOs submitted their data to the State and it was uploaded to CMS.

“In 2019, after we learned reporting would be mandatory in 2024, we started transitioning to custom, in-house development, leveraging the State’s data warehouse and focusing on the required measures only,” explains Raju.

“Then, in 2023, we completed our first mock run of the system for 2022 data, resulting in a dip in the Count of Adult Measures Reported.” (See the chart above.) 

In Michigan, the State approached the Child Core Set reporting with a process different from the Adult Core Set. “Depending on the Core Set you are dealing with, you may take a different approach to each,” says Gruszka. 

The State leveraged available support, enrolling in CMS sponsored grants and affinity groups, which helped us gather and implement best practices from other States.

Defining populations and stratifications

CMS defines populations in this way: “Eligible population for measurement. For all measures, denominators must include all Medicaid and CHIP beneficiaries who satisfy all specified criteria (including age, continuous enrollment, benefit, event, and anchor date enrollment requirements).” (CMS Adult Core Set, p. 9)

Medicaid is not simply one program, but rather it is made up of many different programs within each state, each with different benefits. State teams must decide which programs meet the criteria for each measure. Incorporating these populations into the reporting may vary by State and their ability to gather the data. 

For example, in Virginia, Medicare/Medicaid Duals (those who are enrolled in both Medicare and Medicaid) are included in the reporting, and in Michigan they are not. 

“Currently, reporting Medicare/Medicaid Duals is not required by CMS,” says Gruszka. “Many State Medicaid agencies do not have access to Medicare claims. And yet, with the population over age 65 growing, we know this requirement will be coming in the future. So it’s important to start asking, ‘How will we approach this? How will we get the data?’” 

Establishing secure data linkages

After identifying the population and who will be included, the next step is to gather data from a wide variety of sources. Medicaid claims for outpatient, inpatient, pharmacy, behavioral health and dental care may come from disparate sources such as fee-for-service vendors, MCOs and other providers.

In addition to multiple systems, some measures require linkage with public health data, vital records, immunization registries and more. Technological infrastructure, as well as compliance and agreements, may be required.

In Virginia, building two Core Set measures — for immunizations for adolescents and immunizations for children — required an interagency agreement with the Virginia Department of Health. “We couldn’t just say we need the data,” Raju explains. “We had to explain what we needed it for, how we needed it, and then we had to make sure what we got was clean and acceptable.” 

In Michigan, it took a year of working with partners within the Michigan Department of Health and Human Services to develop data use agreements and ultimately gather HIV viral load suppression data.

“We’re all in the same agency, but we did not have access to that data,” Gruszka says. “And that was just a single measure out of 45 or 50 for the Core Set that we needed to gather.” 

Inability to access data from the State’s health information exchange provided additional challenges for the Michigan team. And while creative workarounds yielded the information needed, significant time was spent. Michigan has since developed a long-term solution with an agreement that allows Medicaid to access the exchange’s data.

Gruszka suggests that as State Medicaid employees embark on securing data linkages, they ask 3 questions:

  • How much data do we have as a State?
  • How much data does Medicaid have access to?
  • If Medicaid doesn't have access to the data, how can we get access?

Developing and validating the analytics

When the population is identified and the data is gathered, it’s time to calculate the measures. Michigan and Virginia have taken slightly different approaches to this step.

In Michigan:

  • The State has a license for a large-scale software engine that includes hundreds of measures (including Core Set measures) that all run simultaneously.
  • The software is updated annually, so measure specifications are up-to-date
  • Additional measures are custom-coded
  • Reports from the measures engine and custom queries run quarterly and simultaneously.
  • Data validation is built into the automated process.
  • Data is stored as summary results (numerator, denominator, rate) and at the detail beneficiary level.

In Virginia:

  • Partnering with the data warehouse vendor, a design document is developed before coding the measure.
  • The document captures the requirement, columns and tables to be used in the code.
  • The template is designed to standardize the coding approach across the team and simplify onboarding of new team members.

The State developed a data mart for the Child and Adult Core Set measures, with results stored as summary data and at a beneficiary level. It also captures demographic stratification information beyond what is required by CMS. 

When measures are calculated, how do you confirm that the results are accurate? There are several options for validating measure results, including: 

  • Peer code review
  • Internal benchmarks from previous measure analyses 
  • Data validation meetings with internal/external partners
  • Comparison to national benchmarks
  • External Quality Review Organization (EQRO)

A key element is the ability to stratify results, and Michigan and Virginia have developed stratifications that follow CMS requirements, including age, gender, ethnicity, race, geography and Medicaid/CHIP. They have also developed additional stratifications of state interest, including pregnancy status, comorbid chronic conditions, housing status, health plan, eligibility type and more.

“Both States have found there are many additional stratifications that are useful to help drive quality and identify gaps in care,” says Kreiner. “In terms of demographics, but also social determinants of health and health status stratifications.”

Driving quality improvement

For Virginia, these charts track one measure: follow-up after emergency department visit for mental illness. Data is stratified by region and eligibility category, revealing opportunities for improvement and ultimately resulting in the development of network adequacy dashboards. 

“This is an example of how developing these measures is not just for CMS purposes, but to improve the quality of care for Virginians,” explains Raju.

For Michigan, the graph below reflects stratified results for diabetes short-term complications for MCOs over multiple years, as well as developmental screening by region, revealing geographic variations.

By stratifying many types of factors, the data reveals gaps, and when the gaps are closed rates improve, driving continuous quality improvement. 

“You also can evaluate the impact of policies or additional benefits, like adding a medication to a formulary, and make informed decisions about whether or not services are impactful” says Gruszka. 

For example, this chart reflects data related to doula services added in Michigan just a year ago:

Measures in action

Data informs and empowers the State and health plans so that care and outcomes can be improved.  

In Michigan, MCOs receive quarterly reports on performance toward benchmarks on selected CMS Core Set Measures, including behavioral health, dental care, chronic conditions and maternal health. 

 

  • MCO performance on Core Set measures is incentivized through a range of mechanisms.
  • Multi-year quality initiatives focus on specific measures with low performance.
  • Stratifications identify health disparities.
  • A care management application called CareConnect360 allows MCOs to have access to their agency’s rates and to statewide rates, with export of beneficiary-level details for each measure to monitor progress toward annual goals.

The Virginia Department of Medical Assistance Services (DMAS) developed a data mart that includes Core Set measures that allows for additional state stratification analyses to assist with decision-making.

DMAS uses the data to:

  • Monitor MCO performance more frequently
  • Understand and create collaborative opportunities with MCOs to address gaps in care
  • Monitor specific localities that need improvements

“The approaches taken by Michigan and Virginia reflect state-specific priorities, program features and health IT environments,” says Kreiner.

“Years of preparation have now produced enhanced analytical capacity and a range of tools to support improving population health for both state Medicaid programs.”

Listen to the 2025 Healthcare IT Connect Summit

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