Area Codes United States of America The Area Codes of United States of America: City/Town or Region Area code 1. California 619 (+1 619) 2. California 562 (+1 562) 3. California 628 (+1 628) 4. California 650 (+1 650) 5. California 657 (+1 657) 6. California 661 (+1 661) 7. California 408 (+1 408) 8. California 415 (+1 415) 9. California 424 (+1 424) 10. California 442 (+1 442) 11. California 626 (+1 626) 12. California 559 (+1 559) 13. California 530 (+1 530) 14. California 510 (+1 510) 15. California 323 (+1 323) 16. California 310 (+1 310) 17. California 951 (+1 951) 18. California 949 (+1 949) 19. California 925 (+1 925) 20. California 916 (+1 916) 21. California 209 (+1 209) 22. California 213 (+1 213) 23. California 669 (+1 669) 24. California 707 (+1 707) 25. California 714 (+1 714) 26. California 747 (+1 747) 27. California 760 (+1 760) 28. California 805 (+1 805) 29. California 818 (+1 818) 30. California 831 (+1 831) 31. California 858 (+1 858) 32. California 909 (+1 909) 33. Colorado 719 (+1 719) 34. Colorado 303 (+1 303) 35. Colorado 970 (+1 970) 36. Colorado 720 (+1 720) 37. Connecticut 475 (+1 475) 38. Connecticut 203 (+1 203) 39. Connecticut 860 (+1 860) 40. Connecticut 959 (+1 959)