Do not drive it. That is the whole first step. A notice in the mail, a card payment that did not clear, or a renewal date that simply slipped past can leave a car uninsured without anyone noticing until the letter arrives. Once you know, the safest assumption is that the vehicle stays parked until a policy is confirmed active in writing. Everything else can be handled from a chair with a phone.
First, take the car off the road
Call the carrier before you call anyone else and ask the exact question: is the policy still in force, and if not, what is the effective date of the lapse? Sometimes a missed payment falls inside a grace period and coverage never actually stopped. Sometimes a reinstatement is available within a short window with no gap at all. Neither is guaranteed, but both are common enough that the phone call is worth making before you start applying elsewhere.
While you are on that call, ask for the reason in writing and note the name of the person you spoke with. If the lapse came from a bank error or a notice sent to an old address, that record matters. A correction is much easier to obtain in the first few days than a month later.
Ask about a reinstatement window
Some carriers will restore a recently ended policy without requiring a fresh application, occasionally with no break in coverage if the arrears are paid promptly. Others require a new application, a new rate, and a fresh inspection or vehicle photos. Ask which applies, and get the answer as a date and a dollar figure rather than a general reassurance.
If reinstatement is not available, shop as you would for any new policy: matched limits, a deductible you can actually pay, and every household driver listed honestly. Be upfront about the gap when asked. It will be visible in the records anyway, and an omission discovered later can create a far worse problem than the lapse itself.
What a gap does to the next price
A continuous coverage history is one of the things carriers look at when setting a rate, so even a short break can raise the next premium. The effect varies by company and by state, and it usually fades as a clean history builds again. What matters more immediately is that driving without coverage is illegal nearly everywhere and can carry fines, registration consequences, and personal liability for a crash that no insurer will handle.
Do not be tempted to backdate anything or to describe the gap as shorter than it was. If the car was parked the entire time, say so plainly; that is a different and much more manageable story than a vehicle that was being driven.
The DMV piece people miss
In many states the carrier notifies the motor vehicle agency when a policy ends, and the agency may send its own notice asking for proof of new coverage or the surrender of the plates. Ignoring that letter can lead to a registration suspension, which then has to be cleared separately from the insurance problem. Check the agency's website for what is required where you live, and keep the receipt or confirmation number for anything you submit.
If the car will sit for a while, ask about comprehensive-only storage coverage, but confirm with the registration office first, since dropping liability on a registered vehicle is not permitted in most places. Once a new policy is active, put the current card in the car, set a calendar reminder a week before the next due date, and move the payment to a method that does not depend on remembering a single afternoon.