This project is open to males with any variation of the Coursey or DeCoursey surnames (see below) or to any man believing that he is descended from one of those names. Participants are sought from all parts of the world.

Free and rebated tests are available for participants from certain lineages and places of origin. See the Wanted! page for more information.

Examples of surname variations
Coursey, Corse, Courcey, Courcy, Courci, Course, Corsey, Courson
de Courcy, de Courcey, DeCoursey, DeCourcey, DeCourcy, DeCorsey, DeCourse

Participant Requirements
The region of DNA tested is located on the Y-chromosome, which only males have. It is passed from father to son more or less unchanged, except for random mutations. The tested individual must therefore be a male from an unbroken male (De)Coursey (or surname variant) line, or believe he is descended directly from one.

How to Participate
Males with the (De)Coursey (or variant) surname, or a suspected (De)Coursey paternal line:

• Order a Y-STR DNA test from FTDNA or another testing company of your choice. It is highly recommended that you test at least 37 markers. (See below for FTDNA prices.)
• You may also purchase a test through the National Geographic Genographic Project, and then transfer the test results to FTDNA. (The Genographic Project uses the FTDNA labs for their testing.) The project only tests 12 markers, however, so it would likely be necessary to upgrade to more markers in order to compare results with others on a genealogical level. The cost of a test through the project is the same as a 12 marker test at FTDNA group prices. If you would like to participate in the Genographic project but would rather purchase a test through FTDNA directly, you can have your results included in the project for a $15 fee.

Females (and males with a non-(De)Coursey paternal line):

• Find a male Coursey relative who is willing to take a DNA test.
• If no known male family members exist or they are not willing to be tested, you can try to write to other people researching the same line, they might know of someone who would could take the test. That way you may also be able to share testing costs.
• If you can't find anyone to be tested, have your line added to the project's Wanted! page, specifying how much of the testing cost you are willing to cover. (Email the project administrator for details.)
• Females can also order a mtDNA test for themselves. Mitochondrial DNA is passed from mother to child (both male and female) in the same way as the Y-chromosome is passed from father to son. mtDNA, therefore, is only useful in studying the maternal line, and the results of this test do not pertain to the surname project. Participants (both male and female) may however submit mtDNA results and female lineages of Coursey/DeCoursey wives for posting on the mtDNA page. (Contact the project administrator for more information.)

Click HERE to place an order for a DNA test at Family Tree DNA at group pricing.

Purchasing a Testing Kit
The main testing company for this project is Family Tree DNA, of Houston, TX, the World's leading testing company for Surname DNA Projects. All tests include a Y-haplogroup assignment (an indication of deep ancestry). Participants are welcome to use other testing companies if they would rather do so, although we do recommend using FTDNA. Contact the project administrator for more information. The more markers you have tested, the more relevant matches can be made with project members. More markers also allow for the possibility of being able to separate participant groups into more closely related clusters. We therefore strongly recommend buying the largest number of markers that you can afford. We hope that serious researchers test at least 37 markers.

The following are Family Tree DNA's Y-DNA test prices for group members: (See FTDNA's order page for pricing on mtDNA and autosomal tests and combination packages.)

• Y-DNA 12 marker screening test: $99 (not recommended)
• Y-DNA 25 marker test: $124
• Y-DNA 37 marker test: $149
• Y-DNA 67 marker test: $238
• Y-DNA 111 marker test: $339
• Upgrading from one step to the next: $49
• Upgrading from 12 to 37 or from 37 to 67 markers: $99
• Upgrading from 67 to 111 markers: $129
• Add $2 for US postage and $4 for international postage