Verizon Wireless will soon get rid of its unlimited data plans held by customers who were grandfathered in before the company launched tiered data pricing, according to a report from FierceWireless.

Verizon CFO Fran Shammo reportedly told an audience at the JPMorgan Technology, Media, and Telecom conference today that 3G unlimited data plan holders will eventually have switch to a “data-share” plan. The company’s data-share plans will launch this summer and effectively end single device/single data plan polices. But data-share plans are tiered and anyone upgrading to use a 4G-enabled device must have one.

It’s unclear if Verizon will force all of its users with unlimited 3G data to switch plans if they aren’t switching to a 4G-enabled phone. Apple iPhone 4S customers right now, for example, only use 3G data and have quite some time before their two-year contracts are up. Will they be allowed to use unlimited data until they switch to a 4G-enabled iPhone 5 or Android superphone?

Verizon ditched unlimited data plans last summer, in line with what AT&T has done. Sprint, notably, still offers unlimited 3G and 4G data plans and might even offer unlimited 4G LTE data when its second 4G network launches. T-Mobile still has some unlimited data offers as well, but does not have the iPhone.

We contacted Verizon for clarification on its upcoming data plan options, but a company spokesperson declined to add anything to Shammo’s comments.