Image: Businessmen at lunch © Digital Vision, Getty Images

Earlier this year, Forbes contributor Nancy Anderson wrote about some of the ways that "couples unknowingly sabotage their finances." But as difficult as it can be to manage money in any relationship, it can be even more challenging when that relationship is a domestic partnership, civil union or same-sex marriage. That's because, despite President Barack Obama's recent change of heart, none of those relationships come with all the same rights and privileges as a traditional marriage.

For example, I recently received a question from someone who wanted to know why her employer wanted to charge taxes on the value of health benefits for her domestic partner. It turns out that health insurance for domestic partners isn't eligible for the same federal tax exclusion as benefits for federally recognized spouses, unless the partner is a dependent. If you or someone you know is in a similar type of relationship, here are some other pitfalls to be aware of.

1. You have to file federal taxes as a single person or head of household

This could result in higher or lower taxes than if you filed as a married couple filing jointly or separately. It also means you may want to think about which partner should have tax-deductible expenses and which partner should hold taxable assets. For example, charitable contributions should come from the partner who itemizes taxes or is in the higher tax bracket. On the other hand, taxable bonds would be better held in the name of the person in the lower tax bracket. Just be aware that you'll need to file a gift tax return on gifts more than $13,000 per year per person.

2. There may not be a procedure for a divorce

Depending on the nature of your relationship and what state you live in, there may not be a divorce procedure to ensure that both partners can walk away with their share. That could be a good reason for each of you to keep a portion of assets in your own name. Again, don't forget about the gift tax when contemplating transferring assets.

3. You aren't eligible for spousal benefits from Social Security

Normally, spouses can choose to take a spousal benefit equal to one-half of their spouse's Social Security benefit in lieu of their own benefits and may qualify for benefits as a surviving spouse or divorcée. However, same-sex spouses and unmarried partners are not eligible for these benefits. This can mean a couple of things. First, if one person in the relationship hasn't earned much in terms of Social Security benefits, you may need to save more to make up for the lack of a spousal Social Security benefit that could otherwise help make up the difference. Second, consider carrying life insurance in retirement to make sure each of you is taken care of after the first person dies.

4. If you need long-term care, your home may need to be sold to qualify for Medicaid

Typically, you wouldn't have to sell your home to qualify for long-term-care coverage from Medicaid if your spouse is living in it. However, that's not necessarily the case if you're in a nontraditional relationship, so long-term-care insurance is even more important in that scenario. The good news is that none of your partner's assets would have to be spent down to qualify for Medicaid, so you need to protect only your own assets, including your home.

5. You may not be able to make health care decisions for each other

Having a health care power of attorney to empower someone to make medical decisions for you in case you're unable to is important for everyone, but even more so if you're not in a federally recognized marriage, since your state may defer to blood relatives instead. You can download a free copy of your state's advance directive (which includes a health care power of attorney) at Caring Connections.

More from Forbes: