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Time Warner Cable, Comcast Cable, and Cox Cable charge $7 to $10 per month (and climbing) to lease or rent your cable internet modem from them. (In this review, I use the terms "lease" and "rent" interchangeably). Quick math says you're paying $84 to $120 per year to use their modems.

All three companies allow you to buy your own modem and stop paying the monthly fee. You can easily buy a quality modem for under $85. In any event, the payback is about 1 year. Even if you did need to replace your modem every two years with what might be the latest and greatest, you would still come out way ahead.

My original modem hadn't been updated or replaced by my cable company in at least three years and they still wanted me to pay to rent it. Buying an installing your own modem is a very easy process.

Cable Internet Modem
Your cable internet modem is the small table top appliance that allows you to get on the internet via a signal from your cable company. Your modem's unique MAC ID (found on the box and modem itself) must be registered with, and activated by, the cable company for the modem to work properly.

The easiest way to determine which modem you need is to check your model number (located on the front, back or bottom of your modem) and simply buy the same modem as your current model --- as you KNOW it'll work --- although you'd very likely get better performance with a newer model. If your current model isn't one of the ones listed in the cable provided site lists, then you have an old modem that needs replacing anyway.

You can buy your modem at places like Amazon.com, Best Buy, HH Gregg and Wal-Mart.

Comcast charges about $8 per month to lease the cable modem in your home. They have been charging a modem fee for about 7 years and the rental price keeps climbing. Comcast has a list of Approved Comcast Cable Internet Modems from which you can select.

Cox Cable Internet
Cox charges about $7 per month to lease a DOCSIS 2 (single band) cable modem, or about $10 per month to lease a DOCSIS 3 (dual band) cable modem, in your home. The rental price keeps rising. Cox has a list of Cox Compatible Cable Internet Modems from which you can choose. Note that while DOCSIS 2 modems are on their approved list, they don't recommend them, and neither do I. More about this later.

Time Warner RoadRunner
Time Warner charges about $8 per month (and climbing) to lease the cable modem in your home. Time Warner has a list of Approved Time Warner Cable Internet Modems from which you can select. This page also has good step-by-step instructions on how to set up and activate your new modem with Time Warner Cable.

Charter Cable
If you are a Charter customer, this page will not help you. In 2012 Charter got into big trouble for failing to track which customers used Charter-provided modems and which owned their own modems, and got caught charging too many of the wrong customers a recurring rental fee of $7 month. Upon renewal of their annual contracts, Charter quit supporting personal modems and stopped assessing the monthly rental charge (although the fee will likely be included in the monthly internet price). Am I the only one that finds this a little humorous?

Buying Hints
  1. There are lots of modems that look similar to the approved modems. Be sure to get the EXACT model number shown in the approved lists.
  2. Although you can make due with lower end models if you have basic internet service, I strongly recommend you consider buying a DOCSIS 3 model that is also IPv6-ready.
  3. DOCSIS 3 modems (also known as "Dual Band") are simply faster modems than DOCSIS 2 (also known as "Single Band") due to their ability to double the download speed bandwidth. Most folks will see an improvement with a DOCSIS 3 modem. Keep in mind that the cable companies often increase the internet speed of their entire system from time to time. The speeds you have today are higher than the speeds they provided a decade ago on the same service plan. DOCSIS 2 modems are cheaper for a reason. Don't fall into that trap, unless you never want higher internet speeds.
  4. The Internet is transitioning from shorter Internet Protocol (IP) addresses (aka IPv4) to longer Internet Protocol (IP) addresses (aka IPv6) due to a shortage of short addresses. To make sure that the Internet can keep growing, a new numbering system called IP version 6 (IPv6) is being deployed and at some point IPv4 modems will not be able to connect to the new addresses. IPv6-ready modems will allow you to access all of the internet addresses now and after the IPv4's are no longer supported.
  5. Yes, you can also replace your Gateway modem (a modem with a built-in Wi-Fi router) and discontinue your rent payments.
Two years ago, I personally replaced a Motorola SB5101 with the SB5101U and found no difference in connectivity. I've been very happy with the reliability of the SB5101U modem. However that was a DOCSIS 2 modem and when my cable company recently promoted me to a faster internet speed I was unable to take advantage of it. Bummer. So after some significant research, I bought a new Motorola SB6141 (white) DOCSIS 3 modem. While my current speed isn't currently 8x faster (as I'm not willing to pay the cable company for higher speeds), I did verify a solid 23% boost in speeds.

To make things easy, the two models shown below are approved by all 3 cable companies. Both of these are DOCSIS 3.0 models. A DOCSIS 3.0 cable modem is backwards compatible, so you can buy one of these even if you currently have a DOCSIS 2.0 modem. Suffice it to say the dual band feature of the DOCSIS 3.0 modem is up to 8x faster. Buy the white SB6141 if you have a router. Buy the black SBG6580 if you don't.

Motorola SurfBoard SB6141 DOCSIS 3.0 Cable Internet ModemThe Motorola SurfBoard SB6141 DOCSIS 3.0 Cable Modem can be bought online from Amazon for under $95. This modem is white. The LED lights on this modem are so bright they can be used as a night light. If this is a problem for you, simple apply a piece of opaque tape to the front panel. If you already have a router, this is the one to choose between these two. (Caution: A black-colored SB6141 is also available. Don't buy it! Even though it's usually a couple dollars cheaper, it's an older OEM model which has no warranty, may not have the most current firmware, and may have been remanufactured).
Motorola SURFboard Gateway SBG6580 DOCSIS 3.0 Wireless Cable ModemA Motorola SURFboard Gateway SBG6580 DOCSIS 3.0 Wireless Cable Modem can be bought online from Amazon for under $130. The SBG6580 includes an 802.11n wireless access point with dual band capabilities, as well as a 4-port Gigabit Ethernet router. It supports WPA, WPA2, WEP, and WPS wireless security, wireless video streaming, wireless printing, and hosts the WiFi signals that your other devices like your Kindle, cell phone apps, laptop computer, and TV might use.


  1. View the list of approved retail modems for your tier of Internet service using the links above for Comcast and Time Warner. (If you are also a Comcast, Cox, or TWC Home Phone customer, please read the Home Phone FAQs on their sites for additional instructions.)
  2. Buy your modem at a local retailer or online. Connect your modem at home using the instructions provided by the manufacturer. If you are replacing an identical or similar modem (SB6141 for example), all you need do is change out the modem by unplugging the Ethernet, Cable, and Power cords from the old modem and plugging the three cords into the new modem. Be sure to replace your old power supply with the new power supply which came with the new modem.
  3. Call your cable company's Customer Care Department to activate your new modem on your Internet service. Provide the Cable Modem ID (MAC address), usually found on the bottom of the modem as well as the box it came in. Note that some companies offer an online installation option. You can also try contacting them via live chat if you don't wish to call.
  4. They may require you to reboot your system. Simply unplug your new modem (and unplug your router if you have one), wait 10 seconds and plug both back in, restart your computer. Open a browser and check for internet activity.
  5. Once your new modem is activated, drop off your leased modem at the local cable store. You must return the leased modem to stop the monthly recurring Internet Modem rental fees.
  6. When you call, you can often request a box with a shipping label to return the rented modem so you don't have to go to the service center yourself.
  7. If you have internet phone service the cable companies usually include the modem in the cost of the phone service and don't want you to change modems.
Here are four related links which you may find helpful:
Connect and Watch Internet Content on Your TV
Greater detail on internet ready HDTVs and the why you should consider steaming internet content, like Netflix, on your TV.

Expanding Reliable WiFi Internet Access Throughout Your Home
Setting up a high power WiFi repeater to broadcast your WiFi signal throughout your home.

Setting Up A Moderately Priced Home Theater Experience
Assistance in selecting and setting up a great moderately-priced home entertainment system.

Eliminate Your Landline Phone Carrier
Detailed information on how to replace your landline service with cell phone service and keep your home phone number.

Information is from sources believed to be reliable but cannot be guaranteed. The information presented is an opinion intended to assist site visitors on purchasing and installing a cable internet modem.

Since we do not have complete control over the "Ads by Google" appearing on this page, we do not directly endorse their sites or products. Please notify us if you find any of the advertisers to be misleading.
© 2012 Topher
Updated 2018

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