3rd class medical now expires in 60 months ?

Today I was informed by my medical examiner that the “Medical
Certificate” for 3rd class now expires after 60 months as opposed to
36 months for pilots under the age of 40 years at the time of
issuance.

I am trying to finish my VFR, but my student certificate expires after
24 months.
The examiner informs me that the next student certificate needs to be
issued by my instructor.

The examiner suggested I visit the FAA website to look up the current
regs, but the copy of the regs on the FAA site is like reading a
dictionary and I was unsuccessful at finding any information on this
subject.

Can anyone provide a link to this reg ? Does anyone have a comment
on the subject ?
The examiner stated that this reg change went into effect two weeks
ago.

Thanks