In a majority of states, no one yet knows which presidential candidates will be on the November ballot. This is partly because in some states, the petition deadline has not passed; in some states, election authorities are still checking petitions; and in some states there are ballot-qualified minor parties that have still not made final decisions as to whom to nominate for President.
States in which the petition, fee, or other paperwork deadline has not yet passed are: Alabama, Arizona, Florida, Hawaii, Kentucky, Louisiana, Mississippi, Nebraska, North Dakota, Oregon, Rhode Island, and Wyoming. August 24 (today) is the deadline in Idaho and Virginia.
States in which the deadline has passed, but election officials are still checking presidential-procedure signatures, or have yet to decide on certain other procedures relevant to presidential ballot access, are: Alaska, Arkansas (revalidation), Connecticut, Maryland, Massachusetts, New Hampshire, New York, Oklahoma, and Tennessee.
States in which it is possible a ballot-qualified party may yet choose a presidential candidate, or replace a presidential candidate with another presidential candidate, are Alaska, Delaware, Florida, Kansas, Michigan, New York, Oregon, and South Carolina. The list in this paragraph does not include various state units of Americans Elect.
States in which courts will determine whether one or two particular candidates get on the ballot are Georgia, Michigan, Pennsylvania, and Vermont.