Filing for a K-1 visa can be a complex and time-consuming process, but it's a necessary step for couples who want to be reunited in the United States. The K-1 visa, also known as the fiancé visa, is specifically designed for foreign nationals who are engaged to U.S. citizens and wish to enter the United States for the purpose of getting married. Here are the steps you need to follow to file for a K-1 visa:

1. Determine eligibility: The first step is to ensure that both you and your fiancé(e) meet the eligibility requirements for a K-1 visa. You must be a U.S. citizen, and your fiancé(e) must be a foreign national who is engaged to you and intends to marry you within 90 days of entering the United States.
2. File a petition: You must file a petition for your fiancé(e) with the United States Citizenship and Immigration Services (USCIS). This petition should include evidence of your relationship, such as photos, letters, and other documentation.
3. Wait for approval: After submitting the petition, you will need to wait for USCIS to approve it. This can take several months, so it's important to be patient.
4. Apply for a visa: Once the petition is approved, your fiancé(e) will need to apply for a K-1 visa at the U.S. Embassy or Consulate in their home country.
5. Attend an interview: Your fiancé(e) will need to attend an interview at the U.S. Embassy or Consulate. During this interview, they will be asked questions about their relationship with you and their intentions for entering the United States.
6. Receive the visa: If the interview goes well, your fiancé(e) will receive their K-1 visa and can travel to the United States.

Overall, filing for a K-1 visa can be a complex and challenging process. It's important to work with an experienced immigration lawyer who can guide you through the process and help you avoid any potential pitfalls. By following these steps and working with a skilled attorney, you can increase your chances of a successful outcome and be reunited with your fiancé(e) in the United States.

Applying for a K-1 visa requires filing of form I-129F [Petition for Alien Fiancé]. After the petition is approved, it will be sent to the U.S. consulate where your fiancé lives. A medical exam, a police certificate, and an interview at the consulate will be required at this step. Upon visa issuance, the fiancé has six months to enter the United States and must marry the U.S. fiancé within 90 days of entry into the United States.