This has had me baffled for a long time. When I'm travelling, I use my iPhone 5 as my Internet connection for my laptop. I have no problem tethering via Bluetooth, and almost no problem* tethering via wifi. But I've never been able to tether via USB. When I go into network prefs on my Mac, the iPhone USB never appears as an option. I recently saw an article online that said for some peculiar reason, you must have iTunes running before you attempt to tether via USB. I tried this as well, but still no luck. The iPhone USB option never appears in the network prefs. I'm running iOS 7.1.2 on the phone and OSX 10.6.8 on my Mac. Tethering has been available since 10.5.x.

* - When tethering via wifi, the iPhone will often not appear in the network list under the Airport menu. I'll have to go into the iPhone's Settings, and toggle Personal Hotspot off and on, before it appears in the Mac's network list. After that, it works fine.

Bob,

You may have already tried disconnecting and reconnecting the USB interface in Mac OS X, but just in case, here is a recently modified Apple Support document.

iOS: Troubleshooting Personal Hotspot

Thanks for the link. I tried what they suggested, but still no luck. It seemed to be aimed more towards solving issues on the iPhone side, and I suspect that my problems are on the Mac side.

Before I started using the iPhone, I used to use a Novatel 3G/CDMA USB modem for my away-from-home internet connections. I'm wondering whether the Novatel installation may have deleted or inactivated some other USB drivers. The Novatel option still shows up in my network preferences, and it is the only one that uses USB. I deleted it from the preferences and I went to the Novatel site and followed their instructions for removing the Novatel software, but it didn't help.

I'm planning to upgrade to Yosemite in the next couple of weeks. So, I'll wait and see if the problem persists after the upgrade.

Same problem here my USB tethering was working with iMac but not MBP. Solved by going to System Pref > Network > clicked on gear icon, added 'iPhone USB 2' clicked 'Apply' and it worked straight away.

The gear icon only gives me options for the currently selected network. If I click the + icon to create a new network interface, the choices are only: airport, ethernet, bluetooth, or firewire.

The pref panel will only show you currently available ports when adding a new interface. make sure your phone is connected and happy to talk with your computer. (iTunes sync completed successfully) Then try again.

They're sync'd. They happily talk to each other with the USB cable. But, still no USB iPhone option in Network prefs.