No one affirmatively notifies your insurance company of your DUII arrest — unless there was a wreck of some sort. If there was a wreck, you should promptly notify your insurer so they start working to pay whoever got their property damaged or was hurt.
But in non-wreck DUII cases, it is in your financial interest (keeping your premiums low) to not affirmatively notify your insurance company. You have no obligation to do so. On the other hand, you also cannot lie — an affirmative lie could nullify your coverage (fraud). Therefore, my advice in this situation is: don’t change your policy. Don’t buy a new car, don’t add a new driver, don’t establish a new primary residence. Those things would all trigger you having contact with your insurance company. They would then set a new rate for you — based on the new car’s value, or the new driver’s driving record, or the new address (address is used in setting rates because some neighborhoods engender more claims than others / are more dangerous than others). Most rate-setting would include a review of your current driving record. Insurance companies generally use a 3-year look-back policy, so if you can make three years from the arrest without the insurance company finding out about your DUII charge, then you should keep your rates as they are. If you are in a situation where you are asked a direct question by your insurance company about the DUII, you must be honest. That is because their obligation to indemnify (pay for claims) is tempered by your duty of cooperation (honesty).
The above is general advice. You should review your policy terms — maybe you have an insurance policy that requires you to notify your insurer of a DUII arrest. I’ve never seen one. However, I have seen employment and professional policies that either require or strongly suggest you notify your employer or your professional licensing board. For instance, as an attorney I would promptly notify the Oregon State Bar if I was arrested for DUII. With professional licensing boards, it seems to always be better to notify early. If things get sticky, or you’re unsure of how to proceed, it’s best to contact an attorney who specializes in this area.
To sum up: if you get a DUII, you don’t have to immediately advertise that fact to your insurance company. If anyone was hurt or if property was damaged, you should open a claim with insurance promptly. And finally, if you occasionally drink and drive (it’s legal, see my blog post here: http://oberlaw.com/uncategorized/not-illegal-to-drink-drive-court-surprised/) you should have policy limits well above the minimum $25,000/$50,000 limits. Hit one Tri-Met or utility box, and you’ll eat that up immediately — and you’ll be personally on the hook for the remainder. There’s not one DUII lawyer I know who is not insured at the $100,000/$300,000 level, often with a $1,000,000 umbrella policy. It is pretty cheap to increase coverage — and much easier than sitting in a debtor’s prison for failure to pay restitution.