Washington law allows a person to receive a deferred prosecution only once. Using it on a first arrest means it is unavailable if there is ever a second.
Entry into deferred prosecution requires alleging that the offense arose from alcohol or drug dependency or a mental health condition, supported by a professional evaluation. It is not a general second-chance program.
A deferred prosecution petition includes agreeing that the police report may be used as the facts if the program fails. The right to contest the stop, the test, and the arrest is given up at signing.

Treatment runs about two years intensively, but court supervision and review hearings extend to roughly five before dismissal. The case stays open that entire time.
Most Washington drunk driving cases end in one of three ways, and the choice among them is usually made in the first few months, before the defendant has any real feel for the evidence. Each path carries a different price, a different set of obligations that run for years after the courtroom part is finished, and a different mark on the driving abstract that insurers and employers can pull. One of the three can be used only once in a lifetime. A careful reader compares them on the same five measures rather than on how each one sounds when a lawyer describes it in a consultation.
Deferred prosecution under Washington's statute is not a dismissal offered for good behavior. The petitioner has to allege that the conduct arose from alcohol dependency, drug dependency, or a mental health condition, submit to a professional evaluation supporting that claim, and stipulate to the police report as the facts of the case. That stipulation is the whole trial, compressed into a signature. Two years of intensive treatment follow, then supervision running to five years, with review hearings along the way, and the charge is dismissed at the end. A person may be granted one deferred prosecution, ever.
The common negotiated outcome is a plea to a lesser charge, most often reckless driving or negligent driving in the first degree, with the original count dismissed. It avoids the mandatory jail and license consequences attached to a conviction on the DUI count itself, which is why it is offered and why it is taken. The reduced charge is still treated as a prior offense if there is another arrest within the statutory lookback period, so the second case starts from a worse position. Washington also restricts vacating convictions that were originally filed as impaired driving, so the record question deserves a direct answer before the plea, not after.
A district court jury trial on a misdemeanor DUI is short, often a day or two, but the preparation behind it is not. Suppression motions, subpoenas to the toxicology lab, records requests on the breath test instrument, and an expert review of the blood draw all sit upstream of the trial date and all take billable hours. An acquittal leaves no conviction and no sentence, though the arrest itself and the separate license action taken by the Department of Licensing follow their own track. Trial is the only path where the state has to prove anything, and the only one that preserves every appellate issue.
Ignition interlock time is the obligation people underestimate, because it is measured in months of daily inconvenience and monthly vendor fees rather than in a single court payment. Deferred prosecution ordinarily carries an interlock requirement for a substantial stretch of the supervision period. A reduced charge may carry a shorter one, or none, depending on the plea terms and on any parallel administrative action. The National Highway Traffic Safety Administration oversees federal impaired driving countermeasures, and interlock programs sit within that field, but the length of any individual requirement is set by the Washington court and the licensing agency, so the number to ask for is the one in the proposed order.
Ask which dispositions this prosecutor's office actually grants in this courthouse, since county practice varies more than the statute suggests. Ask what the quoted fee covers and where it stops: whether motions, a trial date, and five years of deferred prosecution review hearings are inside the number or billed separately. Ask what the treatment provider charges monthly, because that money is paid by the defendant and dwarfs some legal fees. Ask what appears on the abstract under each outcome, in the words that will appear there. Then ask which option forecloses which others, and by what date.
The comparison only works if the same five columns are filled in for all three paths, with real numbers where numbers exist and a plain statement of the unknown where they do not. A lawyer who will sit down and do that on paper is giving the reader something more useful than a prediction.