• Some Canadians may be inadmissible to enter the United States.USA Flagge image by glockemann from Fotolia.com
  
  U.S. immigration law generally does not require Canadian citizens to apply for a nonimmigrant visa to visit the United States. However, certain restrictions apply to this exemption depending on the purpose of the trip and the applicant's criminal history, if any. In such cases, the Immigration and Nationality Act (INA), also referred to as the McCarran-Walter Act of 1952, outlines situations under which a Canadian must apply for a nonimmigrant visa.
  
  

K-1 Visa

• A K-1 visa is a nonimmigrant visa issued to the foreign fiance of a U.S. citizen. This visa allows the foreign national to enter the United States for the purposes of getting married to her U.S. fiance.
  
  If you and your U.S. fiance would like to get married in the United States, you must apply for a nonimmigrant visa, regardless of your Canadian citizenship status.
  
  

K-2 Visa

• A K-2 visa allows the foreign fiance of a U.S. citizen to bring his minor children to the United States legally. If you and your minor children would like to reunite with your U.S. fiance, you must apply for this visa.
  
  

K-3 Visa

• If you are a Canadian and you are the foreign spouse of a U.S. citizen, you must apply for a K-3 visa if you would like to reunite with your U.S. spouse. You may not enter the United States for this purpose without applying for a K-3 visa.
  
  

K-4 Visa

• If you are a Canadian who is married to U.S. citizen, you have minor children and would like to bring them to the United States, your Canadian children may not enter the United States without a nonimmigrant visa. You must apply for a K-4 visa on behalf of your children.
  
  The K-4 visa requirement applies to the minor children of the spouse, regardless of whether the U.S. spouse is the biological parent of the children or not.
  
  

V-1 Visa

• Canadian citizens who are married to U.S. permanent residents are required to apply for a visa if they would like to reunite with their spouse while waiting for U.S. Citizenship and Immigration Services (USCIS) to complete their immigration process. If you are considering visiting the United States for this purpose, you must apply for a V-1 visa.
  
  

V-2 Visa

• If you are a Canadian who is married to a U.S. permanent resident and you have minor children, you can apply for a V-2 visa on behalf of your children. A V-2 visa allows your Canadian children to enter the United States legally, while waiting for USCIS to complete their immigration process.
  
  

A and G Visas

• U.S. immigration law requires Canadian government officials moving to the United States to apply for the A visa. Similarly, if you are a Canadian and you are an employee or official of an international organization in the United States, including NATO officials, you may not enter the country without applying for the G visa.
  
  

E-2 Visa

• Canadians who are treaty investors may not enter the country without a visa. If you are a treaty investor, U.S. immigration law requires you to apply for the E-2 visa before entering the United States.
  
  

Inadmissibility under INA

• U.S. immigration officers or Customs and Border Protection (CBP) officers may deny a Canadian entry into the United States if she violates one or more of the provisions stipulated in the INA. Grounds for denial may include, but are not limited to, a communicable disease, prior criminal record involving offenses related to moral turpitude, possession or trafficking in a U.S. controlled substance and trafficking in humans.
  
  If you are a Canadian who has committed one or more of these types of offenses, you must file Form I-192, Application for Advance Permission to Enter as a Non-Immigrant and Inadmissible Canadian Information, with U.S. Customs and Border Protection (CBP).
  
  You may not enter the United States without first receiving approval of your Form I-192.