Association of the New York State Marriage Equality Act With Changes in Health Insurance Coverage

When states recognize same-sex marriage, some workplaces are required to offer employer-sponsored health insurance (ESI) to married same-sex couples.¹ Research found laws establishing domestic partnerships for lesbian, gay, bisexual, and transgender (LGBT) populations increased health insurance coverage for lesbian women.² On July 24, 2011, New York State began licensing same-sex marriages under the state’s Marriage Equality Act, and at least 12 280 marriage licenses were issued to same-sex couples in the following 18 months.³ This study investigated the association between legalizing same-sex marriage in New York and changes in health insurance coverage in men and women.

This study used data from the 2008-2012 American Community Survey, a nationally representative mail survey conducted annually by the US Census Bureau, with an annual sample size of approximately 3 million housing units and a 97% response rate.⁴ Follow-ups for nonresponse are conducted by telephone and in-person interviews. This survey does not ascertain sexual orientation; same-sex couples were identified when the primary respondent identified another person of the same sex as a husband, wife, or unmarried partner.⁵

The primary respondent reports current health insurance status for each household member. If multiple sources of coverage were reported, the primary source of insurance was assigned in the following order: (1) Medicare; (2) ESI through a current or former employer, TRICARE or other military health care; (3) Medicaid; (4) insurance purchased directly from an insurance company; and (5) uninsured.

Two-tailed t tests and a difference-in-differences approach were used to compare changes in health insurance coverage between adults in same-sex relationships and opposite-sex relationships. Linear probability models adjusted for factors associated with coverage, including age, race/ethnicity, citizenship, disability status, the presence of a child in the household, education, and year fixed effects. The coefficient of interest was the 2012 × same-sex relationship interaction term, reflecting the net change in coverage for adults in same-sex relationships in 2012 vs 2008-2010, minus the underlying trend among adults in opposite-sex relationships.

All data from 2011 were excluded as a washout period; 2013 was not included because the US Supreme Court ruled portions of the federal Defense of Marriage Act unconstitutional, making it easier for LGBT workers to add a same-sex partner to ESI. All samples were restricted to New York adults aged 26 to 64 years with a partner aged 26 to 64 years. Regression models were estimated separately for men and women using Stata version 12 (StataCorp) and sampling weights. Two-sided P < .05 was considered statistically significant. This study was deemed exempt by the University of Minnesota institutional review board because data were obtained from publicly available sources.

The 2848 adults in same-sex relationships were less likely to have children and reported higher educational attainment compared with the 228 470 adults in opposite-sex relationships (20% vs 55% had children, respectively; 63% vs 39% had college degrees). Both groups had parallel trends in ESI coverage until the implementation of same-sex marriage; ESI coverage increased significantly among adults in same-sex relationships in 2012 (Figure).

Compared with men in opposite-sex relationships, same-sex marriage was associated with a 6.3 (95% CI, 0.7-12.0; P = .03) percentage point increase in ESI and a 2.2 (95% CI, 0.5-4.0; P = .01) percentage point reduction in Medicaid coverage for men in same-sex relationships (Table). Same-sex marriage was also associated with an 8.9 (95% CI, 3.0-14.8; P = .003) percentage point increase in ESI and a 3.9 (95% CI, 1.1-6.8; P = .01) percentage point reduction in Medicaid coverage for women in same-sex relationships vs women in opposite-sex relationships.

The implementation of New York’s Marriage Equality Act was associated with substantial increases in ESI and smaller reductions in state-funded Medicaid assistance for men and women in same-sex relationships. Limitations include the observational design, short follow-up, missing health information, unknown generalizability to other states, and possible inaccuracy or response bias in self-reporting a same-sex partner (particularly after same-sex marriage was legalized); however, the American Community Survey remains the predominant source for measuring same-sex households⁵ and health insurance in the United States.

The US Supreme Court will soon determine whether states are required to recognize same-sex marriages. Based on New York’s experience, a favorable decision may extend access to ESI to LGBT couples.

Correction: This article was corrected online January 26, 2016, to add the word “education” to a sentence in the Methods section and in Table footnote “d.”

Corresponding Author: Gilbert Gonzales, MHA, Division of Health Policy and Management, University of Minnesota, 2221 University Ave SE, Minneapolis, MN (gonza440@umn.edu).

Published Online: June 26, 2015. doi:10.1001/jama.2015.7950.

Author Contributions: Mr Gonzales had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Conflict of Interest Disclosures: The author has completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest and none were reported.

Funding/Support: This project was supported in part by a doctoral dissertation fellowship from the University of Minnesota Graduate School and grant 70469 awarded to the State Health Access Data Assistance Center from the Robert Wood Johnson Foundation.

Role of the Funder/Sponsor: The University of Minnesota Graduate School and the Robert Wood Johnson Foundation had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

Additional Contributions: I am thankful to Lynn Blewett, PhD, Bryan Dowd, PhD, Kathleen Call, PhD, and Ezra Golberstein, PhD (all with the University of Minnesota), and Thomas Buchmueller, PhD (University of Michigan), for their helpful comments without compensation on previous versions of the manuscript.