Uh, it isn't. In fact, I found out that your existing medical is *DEAD*
upon filling out the official form for a new medical. I found that out
when I had to report an irregular heart beat and had to do the Holter
monitor, Stress EKG and echo-cardiograph (they use a sonogram to
examine your heart to see if it has valve problems, etc.).

I had thought that my old Class III was still valid and was flying with
it. The senior AME that had to review all the records I took him
informed me that my old medical was dead the moment my pen hit the new
official form!

And because I had all the paperwork already done (thank you AOPA) and
was able to submit it to that Sr AME, he decided to issue the Class III
and make the FAA Medical people issue a cancellation -- because it is
only noticeable by me at rest!

Later,
Steve.T
PP ASEL/Instrument

ps. I just have an irregular heart beat. But now that I've gone through
all this, I should easily pass the Class I.