By law, Kentucky has closed party primary elections. You must register as a Democrat or Republican to vote in either party’s primary election. If you choose to register in a political group or organization or designate independent status, you will not be eligible to vote in Republican or Democrat party primary elections. However, you are eligible to vote in nonpartisan primary elections. All eligible registered voters, regardless of party affiliation, may vote in general and special elections.
For more complete information please download and read this document about Voter Registration in Kentucky.