Contact Verizon and ask.
But my knowledge says if your iPhone is unlocked and the model is Model A1778* or Model A1784* it will not work with Cellular Service provider who provide only CDMA SIM
Model A1660*
Model A1661*
FDD-LTE (Bands 1, 2, 3, 4, 5, 7, 8, 12, 13, 17, 18, 19, 20, 25, 26, 27, 28, 29, 30)
TD-LTE (Bands 38, 39, 40, 41)
TD-SCDMA 1900 (F), 2000 (A)
CDMA EV-DO Rev. A (800, 1900, 2100 MHz)
UMTS/HSPA+/DC-HSDPA (850, 900, 1700/2100, 1900, 2100 MHz)
GSM/EDGE (850, 900, 1800, 1900 MHz)
Model A1778*
Model A1784*
Models A1778 and A1784 do not support CDMA networks, such as those used by Verizon and Sprint.
FDD-LTE (Bands 1, 2, 3, 4, 5, 7, 8, 12, 13, 17, 18, 19, 20, 25, 26, 27, 28, 29, 30)
TD-LTE (Bands 38, 39, 40, 41)
UMTS/HSPA+/DC-HSDPA (850, 900, 1700/2100, 1900, 2100 MHz)
GSM/EDGE (850, 900, 1800, 1900 MHz)
https://www.apple.com/iphone-7/specs/