Can You Marry Your Cousin? Colorado Family Marriage

A family tree with three generations.

Can You Marry Your First Cousin in Colorado?

Yes. Colorado law permits first cousins to marry without restriction. Someone called our office last week with a simple question about whether it was permissible to marry a cousin. While we unfortunately are not able to give out legal advice over the telephone (state bar concerns, plus our professional liability insurance carrier would have conniptions), there’s no harm in answering the question publicly (and anonymously) on this blog.

Pursuant to , the following relatives may not marry one-another:

  • Ancestor & Descendant (i.e. parent/child, grandparent/grandchild, etc)
  • Siblings (i.e. sisters or brothers)
  • Aunt/Uncle & Niece/Nephew, although this ban has an exception for “marriages permitted by the established customs of aboriginal cultures.”

In Colorado, the prohibitions are absolute, and do not depend upon whether one spouse is able to bear children, or whether the relative is half-blood or whole blood. Contrast that to some states, such as Arizona, Illinois & Indiana, where cousins are only permitted to marry if both of them are over 50, or one of them is infertile. Because Colorado has no such restrictions, there are occasional news reports about the state being a “destination” for first cousins from other states who wish to marry.

For a complete listing of the legality of marrying cousins in each state, see this Wikipedia article.

How About Birth Defects?

Does marrying your cousin increase the chances of children having birth defects? Yes. First cousins share about 12.5% of their DNA with one-another, and the concern over birth defects is what motivates some states to allow first cousin marriages only when the couple is incapable of having children.

recent study indicates that a child born to first cousins has a 4-7% chance of a birth defect, compared to 3-4% for other children. This was heralded as a reason why the concern over birth defects is overblown. But taking the average between both sets of numbers, the chance of a birth defect rises from 3.5% to 5.5% by marrying a first cousin. Still a small number, but that 2 point risk increase is a whopping 57% greater chance of a child with a birth defect – something most parents would rather avoid.

Do Any States Allow Incestuous Marriages?

No. While cousins are treated differently among the states, no state allows marriages between ancestors/descendants or siblings.

Moreover, most states criminalize sexual relations between such family members, even between consenting adults. In Colorado, for example, incest is a felony.  C.R.S. 18-6-301.

How About Royalty Marrying Within the Family?

Royal families have a long history of marrying other royalty to protect the royal bloodline or to cement foreign alliances. However there are a finite (and shrinking) number of royal houses, which necessarily meant marrying relatives (at least in the old days – now they marry us “commoners”). Usually the relatives were more distant than cousins, however.

Historians believe that the Habsburgs, once the most powerful royal family in Europe with an empire ancient Rome would have envied, were weakened and ultimately made sterile by inbreeding. In the 184 years they ruled Spain, nine out of eleven marriages were incestuous.

In ancient Egypt, pharaohs married almost exclusively within their own families, often to their sisters or brothers.

And who can forget one of the most infamous royal families, House Targaryen? For nearly 300 years, from Aegon I to Aerys II, the Targaryens ruled the Seven Kingdoms, and preserved their family’s bloodline with in-breeding. But we all know how that ended: the dragons died off, and the last Targaryen ruler (Mad King Aerys) went mad and was deposed by Robert Baratheon.**

** CAVEAT – When this blog was published, winter was ending in Colorado, but had yet to come in Westeros. We have to wait another three weeks for the much anticipated final season of Game of Thrones on HBO. It is entirely possible that a Targaryen will once again sit on the Iron Throne: Daenerys Targaryen and Jon Snow (rumored son of Rhaegar Targaryen and Lyanna Stark) are both strong contenders. And if they married each other and ruled together, they would be aunt and nephew – prohibited in Colorado, but not Westeros.

What Other Marriages Are Prohibited?

OK, back to Colorado. The other legal requirements for a marriage in Colorado are:

  • Both parties are over 18, or over 16 with the consent of both parents/guardians. C.R.S. 14-2-106(1)(a)(I).
  • Neither party is currently married or in a civil union (that would be bigamy).  C.R.S. 14-2-110(1)(a) & (1)(a.5).

Legal Effect of a Prohibited Marriage

A marriage which is void is void, and subject to annulment (called “declaration of invalidity of marriage” in Colorado. And marriages which were not prohibited, but entered into as a jest or date, based upon fraud, etc, may also be subject to annulment.

For complete details, see the Annulment in Colorado article in the Colorado Family Law Guide.

More Information

For more information about the requirement for a legal marriage in Colorado, see the Entering into Marriage article in the Colorado Family Law Guide, or if your situation involves a common law marriage, the Colorado Common Law Marriage article.

Award-Winning Family Law Attorney In Colorado Springs

U.S. News & World Report calls Graham.Law one of the Best Law Firms in America, and our managing partner is a Colorado Super Lawyer. Our family law attorneys have years of experience helping clients navigate the Colorado legal system. We know Colorado divorce & family law inside and out, from complex multi-million dollar property or child custody cases to basic child support modifications.

For more information about our top-rated El Paso County family law firm, contact us by filling out the form on the right or calling us at (719) 630-1123 to set up a free consult, or click on:

Colorado Family Law. Period.

Testimonials

  • Excellent discussion; fully answered all my questions with examples I could clearly understand

    Jane Rohr Avatar
    Jane Rohr
    3/26/2020
  • Carl Graham is by far the best divorce attorney I have used and would highly recommend him to anyone who is looking for an ethical, knowledgable, fair attorney. My case was not your normal circumstanc... read more

    Gary Oldguy Avatar
    Gary Oldguy
    3/17/2020
  • As a former military spouse trying to collect my share of my ex's military retirement from California when the divorce decree and all the supporting documents were filed in Colorado i was apprehensive... read more

    Janine Pandher Avatar
    Janine Pandher
    3/01/2020
  • Where do I begin? Well AFTER have a consultation with another attorney ( who made me feel as though i was undeserving of his expertise) I was extremely apprehensive when coming to Graham Law. This was... read more

    Chris Whitfield Avatar
    Chris Whitfield
    2/07/2020
  • Mr. Carl Graham, Cindi (his paralegal), and the rest of his office staff helped us with a military divorce. Mr. Graham is very knowledgeable about military ways and processes. I appreciated the fact... read more

    Shelle Dier Avatar
    Shelle Dier
    1/08/2020
  • If you are searching for a divorce lawyer, first I would like to say I’m sorry you are going through this. It isn’t and easy road. I know sometimes things just don’t work out to save your marriage. Ho... read more

    Trevor Lisby Avatar
    Trevor Lisby
    11/26/2019
  • If you are searching for a divorce lawyer, first I would like to say I’m sorry you are going through this. It isn’t and easy road. I know sometimes things just don’t work out to save your marriage. Ho... read more

    Trevor Lisby Avatar
    Trevor Lisby
    10/30/2019
  • I called Graham law firm to schedule a consultation and spoke with Corinna. When beginning your search for information with any family matters there are many questions and a sense of anxiety of the u... read more

    Kathlena Williams Avatar
    Kathlena Williams
    8/26/2019
  • I was divorced in CO but moved to TX & had issues with my divorce decree from a previous attorney- after referrals from several other firms in CO regarding the best military law firm I went with Graha... read more

    Sarah DeLorean Avatar
    Sarah DeLorean
    8/26/2019
  • Very helpful initial meeting.

    Steven Babbitt Avatar
    Steven Babbitt
    6/26/2019
  • Carl and his team are awesome and super easy to work with. His knowledge is tremendous and he quickly handled my case despite me being across the country. I would do business with his team again and... read more

    Michael Brooks Avatar
    Michael Brooks
    5/26/2019
  • I was impressed by Graham Law in general but most impressed with Brian Boney. Brian is an excellent family law attorney. Attentive, detail-oriented, and hard-working, Brian surpassed my expectations f... read more

    Robert Weeks Avatar
    Robert Weeks
    5/26/2019
  • Mr. Grahm was professional, knowledgable and very prepared. He was also kind and understanding. He knew his military in's and outs. Because of this is got exactly what I was asking for... a swift a... read more

    MAMCO STAFF Avatar
    MAMCO STAFF
    4/26/2019
  • I had the unpleasant task of taking my ex back to court. Carl was the person for the job. His attention to detail and professionalism got me the result I needed. Sincere thanks to Carl and his great s... read more

    Lisa Bruinsma Avatar
    Lisa Bruinsma
    4/26/2019
  • This firm is quite wonderful....very family and military oriented. Compassionate and patient, very understanding and will go to bat for you!!!!! Give them a call!!!!!

    Teresa Wilkie Avatar
    Teresa Wilkie
    4/26/2019
  • Brian did an amazing job helping me with a personal matter! Its not the first time I ask Brian for help, and every time he exceeds my expectations! Thank you for your kindness, understanding and suppo... read more

    Iryna Volynets Avatar
    Iryna Volynets
    4/26/2019
  • Divorce is never easy, but Carl and his warm team helped me navigate this very difficult time. This was a military divorce, so Carl's expertise helped me understand exactly what my options were as a f... read more

    Kara Longmire Avatar
    Kara Longmire
    4/26/2019
  • I have had two occasions that I have needed Carl Graham's assistance with child support issues and both times Mr. Graham and his team were amazing. Mr. Graham is straight forward and honest. I highly ... read more

    Jason Ragland Avatar
    Jason Ragland
    4/26/2019
  • Can't thank the team enough.

    Kevin Czarnecki Avatar
    Kevin Czarnecki
    4/26/2019
  • Very professional and extremely supportive throughout my needs.

    Doyle McNeil Avatar
    Doyle McNeil
    4/26/2019

Contact