• iPadmodels with wireless mobile data access (3G or 4G+LTE), regardless of generation, in the United States are 'unlocked' and not connected to a carrier.
• All iPads purchased straight from Apple are 'unlocked,' meaning they aren't subsidy-locked to any particular carrier. You can select your preferred cellular carrier and switch carriers as your contract allows.
• However, just because the iPad is marketed unlocked does not indicate that any particular model will function with all carriers. It's crucial to pay attention to supported frequency specifics to avoid disappointment, especially on the used market.

Read More: What can you do on an iPad that you can't do on an iPhone?