Financial and tax planning advice is relatively easy to find online for married couples and single individuals. However, according to the U.S. census, about 8% of adults live with an unmarried partner. When you are living with a long-term partner, you may think of yourself as married for most purposes, but the law treats you very differently than it does a married couple. It is important to understand these differences, as they can have a dramatic impact on your lifetime taxes paid. It used to be that if you were LGBTQ+ and in a relationship, you were going to be an unmarried couple, as the federal government did not recognize same-sex marriage. This all changed in 2015, when gay marriage was made legal by a Supreme Court decision. However, many LGBTQ+ couples were long disgusted by the lack of marriage equity and chose to remain unmarried even after the court decision. This means there are still many unmarried LGBTQ+ couples.