(1) Participants who breach their agreements by failing to begin or complete their service obligation, for any reason, including the loss, revocation, suspension, restriction, or limitation of required certification, and other than provided for under paragraph (b) of this section, must repay the portion of all VIOMPSP funds paid to or on behalf of the participant, adjusted for the service that they provided. To calculate the unearned portion of VIOMPSP funds, subtract the number of months of obligated service rendered from the total months of obligated service owed, divide the remaining months by the total obligated service, then multiply by the total amount of VIOMPSP funds paid to or on behalf of the participant. The following formula may be used in determining the unearned portion: A = P((t-s)/t) in which
"A" is the amount the United States is entitled to recover;
"P" is the amounts paid under the VIOMPSP, to or on behalf of the participant;
"t" is the total number of months in the participant's period of obligated service; and
"s" is the number of months of obligated service rendered.