The SR-22, financial responsibility certificate, is required in Virginia if you have an unsatisfied judgment, an uninsured motor vehicle suspension or driver license suspension as a result of a major conviction. It would appear that your husband was required to carry the SR22 because of the latter, a DUI violation conviction.
The VA Department of Motor Vehicles site states that when three years have elapsed from the effective date of the suspension, the DMV relieves the vehicle owner of the requirement of furnishing proof of financial responsibility. Your husband should thus check with the DMV to see if he is released from carrying the SR22 now.
In Virginia being convicted of driving while intoxicated, driving under the influence of alcohol or drugs or driving while intoxicated and maiming are all kept on your VA driving record for 11 years.
Comment Update: Some readers have asked what an unsatisfied judement is. This is a judgement that has not been satisfied.In reference to motor vehicles:
Law provides that vehicle owners and/or drivers must be financially responsible for damages and/or injuries caused by the ownership or operation of their motor vehicle if that vehicle is involved in an automobile accident. The party who is not at fault for the accident (unless compensated for damages and/or injuries), has the right to sue in civil court to recover monetary damages to property and/or for injuries resulting from the accident. If the court awards a civil judgment against the "at fault party" (judgment debtor), and that party fails within a certain amount of days to satisfy the judgment award, this is when there is an unsatisfied judgement.
In every state the laws are different in defining when there is an unsatisfied judgement.