In most cases for K-1 visa applicants, getting a K-1 visa stamped in the passport is a routine process. The only difficulty is the long wait as the petition is processed at the BCIS and as the US consulate conducts its security background check. 

Unfortunately, the granting of a K-1 stamp is not guaranteed. There are some instances where a K-1 fiancee applicant will not receive his/her K-1 visa stamp. These include the following people who

• who have a communicable disease;
  
• are drug addicts;
  
• have committed serious criminal acts, including crimes involving moral turpitude, drug trafficking, and prostitution;
  
• are likely to become a public charge; or
  
• have used fraud or other illegal means to enter the United States.
  
  

The two-year foreign residency requirement 212(e) for former J-1 exchange visitors is also applicable. If found to be ineligible, the consular officer will advise the applicant if the law provides for a waiver.