If a Medicare supplement policy or certificate replaces another Medicare supplement policy or certificate, the replacing issuer shall waive any time periods applicable to preexisting conditions, waiting periods, elimination periods, and probationary periods in the new Medicare supplement policy or certificate to the extent time was spent under the original policy. If a Medicare supplement policy or certificate replaces another Medicare supplement policy or certificate which has been in effect for at least 6 months, the replacing policy may not provide any time period applicable to preexisting conditions, waiting periods, elimination periods, and probationary periods.