Do DUI's from one state count against you when you get one in a different state?

Yes.

Out of state DUI's count if the prosecutor or law enforcement finds them. All of the states talk to each other now, a conviction in one state will potentially appear on the driving record in your state of residency and any other state in which you have been licensed or received a ticket. Since your third offense was recently in Michigan, that can be charged as a felony. If you were only issued a first offense ticket, you may want to consider a quick resolution before someone finds the other two convictions from Florida. Also, be aware, if you receive a fourth conviction, and Florida finds out about numbers 3 and 4, Florida will revoke your driving privileges for LIFE, and no state in the country will ever license you again, unless there is change in the law.

The prosecutor can usually look at your lein record and find them. The police may not have and could have charged you with a OWI First Offense; however, if/when they find out, they could enhance it if your last drunk driving in Florida was within 7 years, or the 3 together were within 10 years, you could be charged with a felony. I would obtain a lawyer in the area where you received your last Michigan offense, usually best to have a local lawyer, who can deal with the prosecutor's office. You have the right to remain silent and did not have to tell them about the previous offenses when you were arrested, but you can't lie, just take the 5th. Your driver license could also be suspended or revoked, depending on how far apart your drunk driving's were. If you were driving on a Florida license, the Secretary of State, will notify Florida if you are convicted. If you were driving on a Michigan license, Florida may not be contacted.

Most states are reciprocal. That means convictions in other states will count against you unless the laws are substantially different. For example a state that has >10 BAC as the standard for OWI may not count a conviction from a stste that has .08 as the threshold. You are probably going to be charged with a felony by Michigan

Yes. They count towards prior offenses. You will certainly need a skilled attorney to handle a third offense.

Under Michigan law, a DUI conviction from another state can be used to enhance the charge in Michgian. If you have 2 priors this could be your third which is a 5 year felony.

States that have reciprocity regarding drivers license listings can count to enhance new offenses. It is possible then, that the new offense would be charged as a 3rd offense-felony. You should have that information already if you have been arraigned and/or had a bond set. Consult with an attorney to discuss further details, options and all possible defenses.