State Estimates of the Number of Uninsured Adults Eligible for a Special Enrollment Period in 2014

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August 2014 | Enroll America


In 2014, uninsured individuals who missed the March 31 enrollment deadline and are not eligible for Medicaid or the Children’s Health Insurance Program (CHIP) still have an opportunity to enroll in health insurance if they experience one of several qualifying events that triggers a Special Enrollment Period (SEP).1 Because of these additional special enrollment periods, millions of currently uninsured Americans could potentially gain coverage through their state or federal marketplace before the next open enrollment period begins. Examples of qualifying life events include permanently moving to an area where different plans are available on the marketplace, getting married, having or adopting a child, and becoming a citizen, national, or lawfully present individual.2 This publication provides national and state-level estimates of the percent of currently uninsured individuals who are likely to have experienced at least one of these qualifying events during the seven months between open enrollment periods and are therefore eligible for an SEP.

It is important to note that the currently uninsured constitute only part of the total population that could become eligible for an SEP. Individuals who lose coverage between open enrollment periods will also often be eligible to enroll in a marketplace plan through an SEP. However, due to data limitations it is not possible to estimate at the state level how many adults are likely to lose coverage over the course of the year.

Key Findings

  • Nationally, almost 7 million adults are likely to experience a qualifying event that could trigger a special enrollment period. This includes about 2.7 million uninsured adults as well as 4 million currently insured adults who lose coverage during the course of the year.3
  • Among the uninsured, approximately 6.5 percent will likely experience one or more qualifying events between open enrollment periods. This corresponds to 2.7 million uninsured adults, or about one percent of the full U.S. adult population age 18-64, based on estimates from 2010-2012, the most recent time period for which reliable state-level estimates are available.
  • Moving constitutes the most common source of qualifying events among the currently uninsured, with an estimated 1.8 million uninsured Americans likely to move to a new county between open enrollment periods.

Estimates are derived from Enroll America’s analysis of the U.S. Census Bureau’s 2010 – 2012 American Community Survey. A detailed explanation of each qualifying event and the share of uninsured individuals likely affected is provided in the following sections, with state-level estimates available in Table 1 in the attached appendix. In addition, some adults will become eligible for an SEP due to other qualifying events not listed here. In particular, gaining permanent resident status or being released from incarceration are both qualifying events. While some individuals who experience these events already have access to health insurance coverage from other sources, others will likely enroll through their marketplace. Estimates for the number of individuals who experience these qualifying events, regardless of current insurance status, are included in Table 2 in the appendix.

Qualifying Events for Special Enrollment Period Among Currently Uninsured


One of the most common ways that an uninsured individual will qualify for an SEP is by permanently moving to an area where new plans are available on the marketplace. Uninsured individuals are more likely to move than the general adult population, with 20 percent of all uninsured adults reporting that they have lived at their current residence for less than one year, compared to just 15 percent of the total population. However, moving alone does not trigger an SEP unless the person gains access to new marketplace insurance options. Moving to a new state satisfies this criteria, but only about 16 percent of all moves are between states. Using currently available data, it is not possible to estimate how many people moving within a state will qualify for an SEP. However, aggregate estimates for the percentage of moves that occur between counties can serve as a proxy for moving to a new marketplace area.4 Nationally, about 38 percent of all moves are between counties. Assuming that the uninsured move counties at similar rates and that moves are distributed evenly throughout the year, this suggests that on average approximately 4.3 percent of the uninsured will move to a new county between open enrollment periods.


Nationally, approximately 2.2 percent of all uninsured adults reported that they had gotten married in the previous 12 months. While marriages do not occur at a uniform rate throughout the year, this suggests that on average approximately 1.3 percent of the uninsured will get married between open enrollment periods.

Having or adopting a child

Nationally, approximately 1.9 percent of all uninsured adults reported giving birth in the previous 12 months (figures on adoption rates among the uninsured are not available but adoption is unlikely to be a major source of SEPs given that only 2 percent of all children residing in a household are related through adoption5). In cases where the father can also claim the child as a dependent, the father will also be eligible for an SEP. Assuming that births are distributed uniformly throughout the year and that fathers generally will qualify for an SEP as well, approximately 2.2 percent of all uninsured adults will have a child between open enrollment periods.

Gaining citizenship

Using the ACS, it is possible to estimate the number of uninsured adults who have gained citizenship in the year that the survey was administered. While this will underestimate the number who have gained citizenship in the previous 12 months since interviews take place throughout each year, the estimates can be benchmarked against administrative data provided by the U.S. Department of Homeland Security. According to the ACS, approximately 411,177 citizens on average reported gaining citizenship each year between 2010 and 2012, while 690,513 adults were actually naturalized on average each year during this period, suggesting that the ACS estimates undercount the number of naturalizations by about 40 percent.6 Since 0.25 percent of all uninsured adults in the ACS survey had gained citizenship that year, and assuming naturalizations occur at a uniform rate throughout the year but are undercounted by 40 percent in the ACS, this means that on average approximately 0.24 percent of the uninsured will become naturalized citizens between open enrollment periods.7

Any qualifying event due to moving, marriage, birth, or naturalization

Some individuals will experience multiple qualifying events—such as getting married and having a child or moving—so the total uninsured population eligible for an SEP is slightly smaller than the total number of qualifying events. Taking this into account, approximately 11 percent of all uninsured adults experienced at least one qualifying event in the previous year, suggesting that approximately 6.5 percent of the uninsured population will become eligible for an SEP between open enrollment periods.8

Click here to download the PDF and view the tables in the appendix.



This piece was written by Ricky Gonzales, Deputy Director of Analytics. Assistance was provided by Zachary Baron, Senior Policy Analyst, Best Practices Institute, and Matthew Saniie, National Analytics and Data Director.

The author wishes to thank John Graves of Vanderbilt University School of Medicine and Jonathan Gruber of the Massachusetts Institute of Technology for their input and feedback on an earlier version of this piece.



1 Special enrollment periods, 45 C.F.R. §155.420. Available at http://www.ecfr. gov/cgi-bin/retrieveECFR?gp=&SID=9045f9b1c870e10cb2133b1ee0e9315d&r=PART&n=45y1. Accessed August 14, 2014.

2 This list is not comprehensive, and some individuals in limited circumstances will also have the opportunity to enroll through an SEP if they were mistakenly directed to Medicaid during the initial open enrollment period or if they were denied coverage for Medicaid in a state that did not expand coverage to adults with incomes below 100 percent of the Federal Poverty Level but subsequently experience an increase in income that makes them eligible for tax credits through the marketplace. See Accessed August 14, 2014.

3 John Graves and Jonathan Gruber, “Obamacare Enrollment is Far from Over,” Talking Points Memo, April 1, 2014. Available at Accessed August 14, 2014.

4 Moving to a new county is neither necessary nor sufficient for triggering an SEP, but counties typically offer different plans in large states. However in some states — including Alaska, Delaware, Montana, New Hampshire, South Dakota, West Virginia, and Wyoming — the same plans are available in all areas, so only moving to a new state would trigger an SEP. For this reason the estimates provided for smaller states likely overstate the share of the uninsured adults who qualify for an SEP due to moving. Plan availability by county for federally facilitated marketplaces and state-partnership marketplaces is provided by U.S. Department of Health and Human Services, Health Insurance Marketplace, “Health Plan Information for Individuals and Families.” Available at Accessed August 14, 2014.

5 Rose M. Kreider and Daphne A. Lofquist, “Adopted Children and Stepchildren: 2010, Population Characteristics,” U.S. Census Bureau, April 2014.

6 James Lee, Department of Homeland Security Office of Immigration Statistics, U.S. Naturalizations: 2011. Available at Accessed August 14, 2014.

7 It is important to note that the ACS does not ask about previous immigration status, but the preamble to a final regulation issued by the Centers for Medicare and Medicaid Services clarified that the special enrollment period for gaining an immigration status “only applies to an individual who was not previously a citizen, national, or lawfully present, as opposed to an individual switching between one of these statuses.” 78 FR 42263 (July 15, 2013). Available at Accessed August 14, 2014.

8 This estimate likely undercounts the total number of individuals who qualify for an SEP since it does not account for fathers who have recently had a child or the undercounting of naturalization in the ACS. However, this should not account for more than a 1 percent difference in the total estimate. The estimate also assumes that about 38 percent of all uninsured who have moved but did not report another qualifying event will be eligible for an SEP due to having new marketplace plans available.

9 U.S. Department of Homeland Security, Yearbook of Immigration Statistics: 2012, Legal Permanent Residents, Table 4. Available at Accessed August 14, 2014. E. Ann Carson and Daniela Golinelli, U.S. Department of Justice, Bureau of Justice Statistics, Prisoners in 2012: Trends in Admissions and Releases, 1991-2012, December 2013. Available at Accessed August 14, 2014.

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