First cousins can marry without restriction in nineteen U.S. states, mostly on the east coast.
Twenty-five states prohibit marriage between first cousins.
Six states allow first-cousin marriages if the couple meets certain criteria, mostly based on age or fertility.
Some states that prohibit first cousins to marry will recognize marriages conducted legally in other states or countries.
Where Can First Cousins Marry In The U.S.?
In this map, the red color shows states where first cousins are prohibited from marrying without exception.
The orange color shows states where marriage between first cousins is allowed under some conditions.
The green color shows states where there is no restriction on first cousin marriages.
Summary Of Cousin Marriage Restrictions In U.S. States
The table below provides a summary of the main factors.
Links to detailed articles
We have an in-depth article for each state in the U.S. that gives you everything you need to know about cousin marriage in that jurisdiction.
These include excerpts from the marriage laws and a link to the full legislation. We also explain the relevant laws in plain English!
Click on the name of the state in the table to jump to the detailed article.
What does “Some Exceptions” mean?
A small number of states allow certain types of first cousin couples to marry. The criteria are usually based on age or infertility.
However, the states aren’t consistent on their age thresholds or what couples need to do to show infertility. We have the full details in the in-depth articles on the specific state.
What does the “Once Removed” column mean?
We are referring to whether first cousins once removed can marry each other.
The children of your first cousins are once removed from you. This isn’t the only way that the relationship works. If you need a full explanation, check out our article on first cousins once removed. [link]
Most states that prohibit first cousin marriages will permit the more distant “once removed” relationship. A small number explicitly forbid “once removed” as well.
What does the “Out Of State” column mean?
The “Out Of State” factor considers whether the state recognizes cousin marriages that were legally conducted outside the jurisdiction.
A small number of states have added this to their marriage legislation. In other states, the Supreme Courts have made judicial rulings in favor of recognizing out-of-state marriages.
You’ll notice that we haven’t filled in yes or no for many of the states. This is because recognition isn’t in their legislation and we can’t find a court ruling.
|STATE||FIRST COUSINS||ONCE REMOVED||OUT OF STATE|
|Indiana||Some Exceptions||Some Exceptions|
|Maine||Some Exceptions *||Legal||Not Recognized *|
|New Hampshire||Prohibited||Legal||Not Recognized|
|North Dakota||Prohibited||Legal||Not Recognized|
What About Half First Cousins?
If you and your partner are first cousins, then you each have a parent who are siblings to each other.
If they are half-siblings, then you are half first cousins. This is genetically a more distant relationship than full first cousins.
A small number of states explicitly prohibit half first cousins in their legislation. We’ve called that out in the in-depth articles.
A History Of U.S. State Laws On First Cousin Marriages
Some states have never had a prohibition on first cousin marriages on their legislation. New York is an example.
But for those that do, is it a recent phenomenon? Let’s take a look back through history.
The influence in many of the states seems to be from religious sectors in the middle or late 19th century.
The Puritans, the Quaker tradition, and the Roman Catholic Church have traditionally been against marriages between first cousins.
It’s worth pointing out that the Methodist Church didn’t take an official position against such marriages.
Nineteenth century laws
Kansas introduced a prohibition in 1859.
These states also introduced bans on first cousin marriages in the 1860s:
- New Hampshire
- North Dakota
- South Dakota
Ohio followed suit in 1870. Then Arkansas introduced a prohibition in 1875 and Illinois in 1887.
Twentieth century laws
Louisiana brought in a first cousin ban at the turn of the century in 1902.
Indiana followed suit a few years later in 1907.
Texas has the dubious honor of being the only state to introduce a ban in this century.
The Lone Star State rolled out its new marriage laws in 2005.
Why Do Some U.S. States Prohibit First Cousin Marriages?
You may be surprised to learn that most Western European countries have no restrictions on marriages between first cousins.
In other cultures, such as India, cousin marriages are quite common.
In the states where Supreme Courts found in favor of recognizing marriages from other jurisdictions, these cases were usually around immigration from such countries.
Why is there such a discrepancy between the United States and Western Europe in this regard?
There seems to be a marked difference in attitudes whereby Americans traditionally see the relationship as somewhat taboo.
Perhaps, the reasons become clearer when we look at the states who apply exceptions based on age or fertility.
The focus seems to be on an increased risk to the health of children when parents share as much DNA as first cousins. However, recent studies have shown that these risks are not much higher than with unrelated parents.
We must acknowledge that the risk increases significantly when there are first cousin marriages in successive generations.