The iPhone 7 and iPhone 7 Plus are being sold by all five major US carriers. But there may be a key flaw in some of the units that would prevent you from switching carriers. Until we get this figured out, our recommendation is that if you intend to switch carriers with your phone, you should buy the Verizon-compatible model at full price.

Apple’s official spec sheet for the iPhone 7 lists two sets of units. Models A1660 (iPhone 7) and A1661 (iPhone 7 Plus) work on all four major US networks and virtual networks like Ting, Ultra Mobile, and Consumer Cellular. Models A1778 (iPhone 7) and A1784 (iPhone 7 Plus), according to Apple’s Web page, do not have CDMA modems and thus don’t work on Verizon, Sprint, or any smaller carrier that uses those networks.

All of the models work equally well on other countries’ networks except on China Mobile, which requires A1660/A1661.

So here’s where things get a little complicated. Last year, we had a similar scare, which turned out to be based on Apple posting a bad spec sheet to its website, which was fixed after a week. So everybody was unnecessarily worried based on what turned out to be a typo.

I sent questions to Apple about this, which haven’t been answered yet. Here’s what we don’t know:

• Do models A1778/A1784 not have CDMA or is that another bad spec sheet? (I’ve asked Apple.)
• Which carrier is selling which models? (I’ve asked carriers; they told me to ask Apple, so I did.)

If you intend to always use your phone on the carrier you buy it for, none of this matters. Your carrier’s phone will work on your carrier.

If you absolutely can’t hold off buying an iPhone until this is resolved, want to have the ultimate carrier flexibility, and you aren’t using Sprint, buy the Verizon model at full price. Verizon and Sprint will have to sell the more flexible model, and Verizon’s full-price phones are all unlocked for use on other carriers out of the box. Sprint can choose whether to activate particular devices on its network, so it’s not a good idea to buy a non-Sprint phone for Sprint until Sprint confirms that it will activate the Verizon units.

Hopefully, this fog will dissipate within the next week and we’ll figure this all out. Check PCMag.com for more updates.