Verizon Wireless now says that existing customers can keep their unlimited data plans. They just won't be able to get a new subsidized smartphone and still keep the unlimited data plan.

On Wednesday, Verizon Communications chief financial officer Fran Shammo told investors during an interview at a JP Morgan conference that the company plans to force many of its existing unlimited data customers to a tiered offering. Verizon Wireless got rid of its unlimited data plan for new subscribers last July. But the company allowed existing smartphones users to keep their $30 a month unlimited data even when they upgraded to new devices and a new contract.

But Shammo said yesterday that Verizon now plans to get rid of those unlimited plans and transition those customers to a new data-share plan that will be introduced later this summer.

"When you think about our 3G base, a lot of our 3G base is unlimited," he said according to a transcript. "As they start to migrate into 4G, they will have to come off of unlimited and go into the data share plan. And that is beneficial for us for many reasons, obviously. So as you pick what tier you want to be and we think that there will be some price up in those tiers."

Verizon's PR team offered little information about the new data plans. And many existing Verizon customers who were grandfathered into the unlimited data plans were left wondering how the new policy would affect them. On Thursday afternoon, Verizon clarified its position.

Now Verizon says that it will allow customers to keep their existing unlimited data plans if those customers either continue to keep their existing device or they buy a new device at the full retail cost of the smartphone.

In other words, if you renew your contract and purchase a subsidized phone, you lose the option to keep your unlimited plan.

"If a 3G or 4G smartphone customer is on an unlimited plan now and they do not want to change their plan, they will not have to do so," Verizon's spokeswoman wrote to me in an email. "(But) when we introduce our new shared data plans, Unlimited Data will no longer be available to customers when purchasing handsets at discounted pricing, i.e. Signing new contracts."

Verizon also clarified that the same pricing and policies once they're announced this summer will apply to all 3G and 4G LTE smartphones. So this means that regardless of whether customers sign a contract for a 3G device or a 4G LTE smartphone, they will still have to give up the unlimited data plan if they buy a subsidized device. It also means that if you already own a 4G LTE phone and have been using the unlimited data plan, you can keep that phone and the unlimited data plan.

Verizon hasn't yet offered any information on the new data-share plans, which will allow people to share data among different people on the same account, much like they do with shared minutes or text messages. The new plans will also allow customers to attach different devices to the same account and share the data. The hope for Verizon is that people will increase their usage and buy more expensive tiers of service that offer more monthly data usage.