Can you use your own modem with your ISP?
It depends on the provider — and the answer is on their own site, usually buried. We track 39 US ISPs: 16 publish an approved-device list, 19 publish technical requirements instead, and 4 don't allow customer equipment at all. Every answer links the ISP's own page.
Two boxes
- Modemtalks to the ISP line
- Routermakes the Wi-Fi
One box — a “gateway”
- Modem + routerone unit does both jobs
Pick your provider
Why does it matter whether you own your modem?
Most cable ISPs charge a monthly fee for rented equipment and publish that fee on their own pricing pages. A compatible modem you own is a one-time purchase — over a typical contract, owning usually costs less than renting. The catch is the word compatible: buy a device your ISP doesn't support and it won't activate, and the return window is your problem rather than theirs. That's the whole reason this site exists — every page starts from what the ISP itself publishes, not from a retailer's claim.
Is a modem the same thing as a router?
No, and the difference decides what you can actually buy. The modem is the box that speaks your ISP's language on the line coming into your home; the router is what turns that single connection into Wi-Fi for your devices. Many ISPs supply one unit — a gateway — that does both. On fiber and satellite services there is often no modem to buy at all: the provider installs its own terminating equipment and the only thing you choose is the router behind it. Each provider page below says which of the two, if either, is yours to replace.
How do we verify these policies?
Every page cites the ISP's own policy page and states when we last read it. Where the ISP names specific devices, we list those exact make and model strings. Where it doesn't, we say so instead of inventing a list. Where two of our own readings of the same source disagreed, we re-read the source before publishing either. Full detail: methodology.