Filling out forms is my "special interest" (if NTs have any).
Call your health insurance company and have Member Services walk you through the form. If they are trying to verify that you are still a student, their form may actually be superfluous and all you have to do is to send documentation to confirm current full-time enrollment at a recognized college or University by the registrar. But check with Member Services first and / or ask for their help.
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O villain, villain, smiling, damnèd villain!
My tables—meet it is I set it down
That one may smile, and smile, and be a villain.
At least I'm sure it may be so in "Denmark".
-- Hamlet, 1.5.113-116