The Human Rights Campaign is a Washington, D.C.-based gay and lesbian lobbying group that tracks companies that offer health benefits to domestic partners. Kim Mills, their education director says, "Companies are doing it because it helps attract and retain good employees." Since last year 34 of the 500 biggest U.S. public companies have started the coverage, bringing the total to 210 companies.

Employers need to keep their eye on social trends and movements to stay current and viable. Organizations do not want to be last in its field to offer this benefit. The trend toward offering benefits to domestic partners built momentum in the 90s with companies such as Apple Computer, Nike and the Gap offering health benefits, and now includes big companies such as Best Buy, General Electric and United Parcel Service.

The cost of covering same sex couples raises overall health care costs by less than 1%, while covering both same-sex and opposite-sex couples increases costs about 3%. The enrollment rates are low, close to 2% of total employees if same-sex and opposite-sex couples are added.

Tax law helps keeps enrollment low because if a domestic partner is added to a policy, then income taxes must be paid on the portion of the premium that covers the spouse. There are no taxes on benefits for legal spouses or children. In addition, the ever-changing state laws regarding same-sex marriages complicate the issue. It's not yet clear whether employers will be required to provide benefits to same-sex married couples. And once companies extend health care benefits to same sex domestic partners it is unclear whether other benefits must be offered. Some companies are offering another benefit, such as bereavement leave, as a test. Others have been amending pension plans to offer pre-retirement survivor benefits to domestic partners.