value of the benefit. Partner benefits are more common among large employers, colleges and universities than at small businesses. The qualifications for and benefits of domestic partnership status vary from employer to employer; some recognize only same-sex or different-sex couples, while others recognize both. According to data from the Human Rights Campaign Foundation, the majority of Fortune 500 companies provided benefits to same-sex partners of employees as of June 2006. Overall, 41 percent of HR professionals indicate that their organizations offered some form of domestic partner benefits (opposite-sex partners, same-sex partners or both). The San Francisco Human Rights Commission maintains a list of health insurance providers that offer insurance plans that cover domestic partners, or employee+1 coverage online: Domestic partner insurance provider search. The Human Rights Campaign Foundation offers best practices on how to implement them (see: Domestic partner benefits ). Taxation of benefits IRS Regulation Section 1.61-21(b)(1) generally requires that the imputed value of the benefit be considered taxable income. For example, if an employee covers his or her partner under an employer health insurance plan, the estimated amount the employer pays to cover the partner will be added to the employee's salary for tax purposes, unless the employee's partner is a qualifying dependent under Section 152. The same is not true for married couples. There are some exceptions that allow for tax-free domestic partner benefits, such as for a domestic partner that qualifies as a dependent under Internal Revenue Code Sections 152(a)(9) through 152(b)(5), a certification and annual recertification that the support and relationship tests of section 152(a)(9) are met, and the relationship between the employee and domestic partner does not violate local law. The proposed Tax Parity for Health Plan Beneficiaries Act would remove these tax inequities. Cities and counties with domestic partnership registries Some U.S. cities offer domestic partnership registries. Some private employers use domestic partnership registrations for the purpose of determining employee eligibility for domestic partner benefits. The following are some examples of such registries. New York City Domestic partnerships in New York City exist for same sex couples and opposite sex couples in which both are above the age of 18 and are New York City residents (or at least one party to the partnership is an employee of the City of New York). The status provides essentially three benefits: (1) the ability to remain in a "rent controlled" apartment after the domestic partner