Getting MAGI Right: An Assisters Worksheet for Determining Household Size in Medicaid and CHIP

Last week, we released a primer on the basics of MAGI – how rules for counting household size and income to determine eligibility for Medicaid and CHIP have been aligned with Marketplace subsidies. The move to MAGI has brought about a number of changes, but to further complicate things, there are some differences that apply only to Medicaid and CHIP. Today, we’re going to feature a new tool designed to help assisters apply the exceptions and adjustments (discussed in yesterday’s blog) in determining the household size for Medicaid and CHIP eligibility.

The Getting MAGI Right series:A Primer on Differences that Apply to Medicaid and CHIP
Differences in Medicaid and CHIP Add Complexity
Exceptions for Who Counts in the Household for Medicaid and CHIP
When Does Social Security Income Count?
Changes to Income Counting Rules in Medicaid and CHIP
Current Monthly Income vs. Projected Annual Income

Over the past year, with grant support from the Robert Wood Johnson Foundation, my colleagues at the Georgetown Center on Health Insurance Reforms and I have been providing technical policy assistance to navigators and certified application counselors in several federal Marketplace states. Last fall, we offered training on a variety of ACA-related topics, including MAGI. During those trainings, assisters told us they needed a tool to help them determine household size, accounting for the situations when there are exceptions and differences apply.

Assisters were clear that they wanted a one-page form to help determine household size. Given the complexity of the rules, this seemed to be a daunting task. But we gave it our best shot – the “our” includes a number of national experts and state-based consumer assisters who reviewed the worksheet and offered input on ways to improve it. I thank them all at the end of the longer brief. Despite our best efforts, I can’t promise that the worksheet is something that someone with no knowledge of the basics of MAGI could pick up and use without help.

Why do we need a worksheet? Eventually, the new MAGI-based eligibility systems will be able to accurately deal with all of the exceptions and differences in Medicaid. But until these systems are fully implemented and fine-tuned, states may continue to rely on human resources – state and county workers – to use their knowledge and judgment in making eligibility decisions. And while the ACA sought to align how eligibility is determined for Medicaid and CHIP with the tax-based eligibility rules that govern Marketplace subsidies, exceptions and differences add complexity to the rules. Additionally, the move to MAGI brought about many changes to how eligibility is determined in Medicaid and CHIP and these changes may be as confusing to eligibility workers as they have been to us. The worksheet helps to account for these differences.

How does worksheet function? The assister worksheet itself is designed to be a stand-alone tool, but it does include a page of more detailed instructions with an example. The goal is for an assister to be able to use the 1-page worksheet alone after they gain an understanding how the tool functions because we’ve embedded the basic rules and noted when exceptions or adjustments apply.

It is important to emphasize that the exceptions and adjustments accounted for in the worksheet apply only to specific individuals, and only in determining eligibility for Medicaid and CHIP. As a result, members of the same household may have a different household size for Medicaid and CHIP from each other. Also, the exceptions and differences do not apply to Marketplace eligibility, where only tax-filer rules apply. Thus, the household size for individuals could be different in Medicaid and CHIP than their household size in determining eligibility for Marketplace subsidies.

Do you have ideas on further refinements to the worksheet? As I noted above, the worksheet has been created in collaboration with others. If you have additional thoughts above how to make it useful, please email me at

Stay tuned for tomorrow’s blog when we drill down on Social Security income. A special thanks to the Robert Wood Johnson Foundation for its support of “Getting MAGI Right: A Primer on the Differences that Apply to Medicaid and CHIP,” the new assister worksheet, and this blog series.

Tricia Brooks is a Research Professor at the Center for Children and Families (CCF), part of the McCourt School of Public Policy at Georgetown University.