5 CFR § 302.203 - Disqualifying factors.
(a) The qualification standards established by an agency or by an administrative level or subdivision of an agency may provide that certain reasons disqualify an applicant for appointment. The following, among others, may be included as disqualifying reasons:
(1) Dismissal from employment for delinquency or misconduct;
(2) Criminal, infamous, dishonest, immoral, or notoriously disgraceful conduct;
(3) Intentional false statement or deception or fraud in examination or appointment;
(4) Habitual use of intoxicating beverages to excess;
(5) Reasonable doubt as to the loyalty of the person involved to the Government of the United States;
(6) Any legal or other disqualification which makes the individual unfit for service; or
(7) Lack of United States citizenship.
(b) An agency may not disqualify an applicant solely because of his/her retired status.