Question about Certificate of Creditable Coverage

When my son purchased his own medical insurance, after taking a semester off from college, there was a waiting period of one year for any kind of mental coverage.  Later, he went back to school, and we added him back to my husband's insurance.  We also kept the coverage he had purchased on his own.  There was no lapse in coverage, but since there was a waiting period on the mental coverage with the insurance he purchased on his own, does that mean that he would not be issued a certificate of creditable coverage on mental claims from that company?  I hope I'm explaining this correctly.  Thanks for your help.