<Li> Fourth round: A total of 12 teams (teams ranked 1--6 by CONCACAF and six third round winners) were divided into three groups of four teams to play home - and - away round - robin matches . The top two teams of each group advanced to the fifth round . </Li> <Li> Fifth round: The six teams which had advanced from the fourth round played home - and - away round - robin matches in one single group (often referred to as the "Hexagonal"). The top three teams qualified for the 2018 FIFA World Cup, and the fourth - placed team advanced to the inter-confederation play - offs . </Li> <P> All 35 FIFA - affiliated national teams from CONCACAF entered qualification . The seeding--used to draw the first four rounds of the qualifiers--was based on the FIFA World Rankings of August 2014 (shown in parentheses). </P> <Table> From the August 2014 FIFA World Rankings <Tr> <Th> Bye to fourth round (Ranked 1st to 6th) </Th> <Th> Bye to third round (Ranked 7th to 8th) </Th> <Th> Bye to second round (Ranked 9th to 21st) </Th> <Th> Competing in first round (Ranked 22nd to 35th) </Th> </Tr> <Tr> <Td> <Ol> <Li> Costa Rica (15) </Li> <Li> Mexico (17) </Li> <Li> United States (18) </Li> <Li> Honduras (43) </Li> <Li> Panama (63) </Li> <Li> Trinidad and Tobago (80) </Li> </Ol> </Td> <Td> <Ol> <Li> Jamaica (85) </Li> <Li> Haiti (117) </Li> </Ol> </Td> <Td> <Ol> <Li> Canada (122) </Li> <Li> Cuba (124) </Li> <Li> Aruba (124) </Li> <Li> Dominican Republic (126) </Li> <Li> El Salvador (127) </Li> <Li> Suriname (131) </Li> <Li> Guatemala (134) </Li> <Li> Saint Vincent and the Grenadines (134) </Li> <Li> Saint Lucia (138) </Li> <Li> Grenada (142) </Li> <Li> Antigua and Barbuda (149) </Li> <Li> Guyana (153) </Li> <Li> Puerto Rico (155) </Li> </Ol> </Td> <Td> <Ol> <Li> Saint Kitts and Nevis (159) </Li> <Li> Belize (162) </Li> <Li> Montserrat (165) </Li> <Li> Dominica (168) </Li> <Li> Barbados (169) </Li> <Li> Bermuda (173) </Li> <Li> Nicaragua (175) </Li> <Li> Turks and Caicos Islands (181) </Li> <Li> Curaçao (182) </Li> <Li> U.S. Virgin Islands (191) </Li> <Li> Bahamas (193) </Li> <Li> Cayman Islands (197) </Li> <Li> British Virgin Islands (201) </Li> <Li> Anguilla (207) </Li> </Ol> </Td> </Tr> </Table>

How many teams qualify for the world cup from concacaf