20 CFR 404.1285: Assessments of amounts due—for wages paid prior to 1987.

(a) A State is liable for any amount due (which includes contributions or interest) under an agreement until the Commissioner is satisfied that the amount has been paid to the Secretary of the Treasury. If the Commissioner is not satisfied that a State has paid the amount due, the Commissioner issues an assessment for the amount due subject to the time limitations in § 404.1286 and the exceptions to the time limitations in §§ 404.1287 and 404.1289. If detailed wage information is not available, the assessment is issued based on the following:

(1) The largest number of individuals whose services are known to be covered under the agreement is used for computation purposes;

(2) The individuals are assumed to have maximum creditable earnings each year;

(3) The earnings are considered wages for covered services; and

(4) The amount computed is increased by twenty percent to insure that all covered wages are included in the assessment.

(b) If the State pays the amount assessed and the assessed amount is later determined to be more than the amount actually due, we issue a refund or credit to that State for the excess amount. When the assessment is issued within the applicable time limitation, there is no time limit on collecting the amount due. An assessment is issued on the date that it is mailed or otherwise delivered to the State.