This collection is every DOCSIS 3.1 cable modem and modem-router combo we sell: Grade A refurbished units tested by hand in the US and backed by our 90-day warranty, alongside new-condition listings from Amazon for models we do not refurbish ourselves. Use the filters to narrow by provider, brand, price, and what is in stock right now, and confirm your exact model on your ISP's approved list before checkout.

What's in this collection

Standalone modems include the Arris SURFboard S33, S34, SB8200, and CM8200, the Hitron CODA and CODA56, the Motorola MB8600 and MB8611, the Netgear CM1000, CM1100, CM1200, CM2000, and CM2500, the HUMAX HGD310, and the rack-mount Ubiquiti UCI. Modem-router combos include the Arris G34, G36, G18, G20, SBG8300, and the refurbished DG3450, the Netgear CAX30S, C7800, and Orbi CBR750, and the Motorola MG8702 and MT8733. Voice-capable models for Xfinity and Spectrum phone customers include the Arris T25 and TM3402 and the Netgear CM2050V.

Not sure which one to buy?

Our guide to the best DOCSIS 3.1 modems by plan and ISP ranks the models here by speed tier, explains which ones support the faster mid-split upload plans, and covers when a combo makes sense. If you already know your provider, shop the filtered lists for Xfinity, Spectrum, Cox, Optimum, or Mediacom.

Why buy a refurbished DOCSIS 3.1 modem from us

Every refurbished unit we ship is reset to factory settings, tested for signal levels and port function, and inspected for cosmetic condition before it goes on the shelf. Since 2015 we have been re-homing working networking gear instead of sending it to a landfill, and a refurbished DOCSIS 3.1 modem performs identically to a new one on your ISP's network. Orders over $49 ship free, returns are accepted within 30 days, and our US-based support team answers by email at support@modemguides.com if activation gives you trouble.

Buying more than one?

Property managers, IT shops, and resellers get 10% off when buying 10 or more items, applied automatically at checkout. Browse the bulk sale collection for eligible listings.

Replacing a rented gateway with a modem you own saves $10 to $25 per month on most legacy cable plans, so the modem pays for itself within the first year. Pick your provider above, choose the model that matches your speed tier, and you are done.