If he said that, he is wrong. Contact your Senator.
USCIS Early Filing Calculator | USCIS
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You may file Form N-400, Application for Naturalization, 90 calendar days before you complete your continuous residence requirement if your eligibility for naturalization is based upon being a:
Permanent resident for at least 5 years; or
Permanent resident for at least 3 years if you are married to a US citizen."