There are multiple ways to select a path to migrate from CDMA to 4G and it depends on device data needs:
If the device is working on 1X or 2G speeds today, then you can migrate to NB-IoT or CAT M1 4G devices. Please check the link for details: https://www.verizon.com/business/products/internet-of-things/connected-assets/lte-category-m1-narrow-band-technologies/
If your device requires 3G or slightly higher data rates or requires voice, then a CAT 1 device can provide cost and performance compatibility.
If you need even higher data rates to improve the user experience of your use cases, then CAT 3 can be an option. Please contact your Verizon representative for help in selecting the correct hardware to fit your needs.