FAA Federal Aviation Regulations (FARS, 14 CFR)

(a) General. The holder of a certificate with an expiration date may not, after that date, exercise the privileges of that certificate.

(b) Student pilot certificate. A student pilot certificate expires 24 calendar months from the month in which it is issued.

(c) Other pilot certificates. A pilot certificate (other than a student pilot certificate) issued under this part is issued without a specific expiration date. The holder of a pilot certificate issued on the basis of a foreign pilot license may exercise the privileges of that certificate only while that person's foreign pilot license is effective.

(d) Flight instructor certificate. A flight instructor certificate:

(1) Is effective only while the holder has a current pilot certificate; and

(2) Except as specified in §61.197(b) of this part, expires 24 calendar months from the month in which it was issued or renewed.

(e) Ground instructor certificate. A ground instructor certificate issued under this part is issued without a specific expiration date.

(f) Surrender, suspension, or revocation. Any certificate issued under this part ceases to be effective if it is surrendered, suspended, or revoked.

(g) Return of certificates. The holder of any certificate issued under this part that has been suspended or revoked must return that certificate to the FAA when requested to do so by the Administrator.