Top Picks at a Glance
| Modem | DOCSIS | Max Speed | Best For | Est. Price |
|---|---|---|---|---|
| 1. ARRIS SURFboard SB8200 | 3.1 | 2 Gbps | Best for 1 Gig plan | ~$120 |
| 2. Netgear CM1000 | 3.1 | 1 Gbps | Best mid-tier pick | ~$90 |
| 3. Motorola MB7621 | 3.0 | 650 Mbps | Best budget for 300 Mbps | ~$60 |
| 4. Motorola MB8611 | 3.1 | 2.5 Gbps | Best future-proof choice | ~$130 |
| 5. Netgear CM2000 | 3.1 | 2.5 Gbps | Best for multi-gig plans | ~$160 |
Verify compatibility at optimum.net before buying. Optimum's approved device list covers their HFC (cable) network only.
Our Picks in Detail
- Speed overhead: 2 Gbps
- Speed overhead: 1 Gbps
- Speed overhead: 650 Mbps
- Speed overhead: 2.5 Gbps
- Speed overhead: 2.5 Gbps
Cable vs. Fiber: The Critical Distinction
Before buying any modem, confirm which type of Optimum service you have. This is the single most important consideration — the wrong purchase is entirely useless for fiber customers.
- Optimum Cable (HFC): Uses coaxial cable. You can use your own DOCSIS modem. This guide applies to you.
- Optimum Fiber (FTTP): Uses a fiber-optic connection terminated at an Optical Network Terminal (ONT) installed on your home's exterior or in a utility closet. The ONT is functionally the modem — it converts fiber optic signals to Ethernet. You cannot replace the ONT with a third-party device. Optimum fiber customers can only add their own Wi-Fi router behind the Optimum gateway in bridge/passthrough mode.
If you have the Optimum fiber product (branded as Optimum Fiber in many markets), stop reading this guide. The savings opportunity here does not apply to your service type.
What to Look for in an Optimum Cable Modem
- Optimum compatibility: Optimum maintains a list of approved modems. Check optimum.net/support/compatible-modems-routers before purchasing.
- DOCSIS version vs. plan speed: Optimum's 300 Mbps plan works fine with a high-channel DOCSIS 3.0 modem. Their 1 Gbps plan requires DOCSIS 3.1.
- Modem-only devices: If you already own or plan to buy a separate Wi-Fi router, a standalone modem is the better choice — cheaper, simpler, and you can upgrade each component independently.
How to Activate Your Own Modem on Optimum
- Purchase a modem from Optimum's approved compatibility list. Note the MAC address printed on the modem label.
- Disconnect Optimum's Smart Router from the coax outlet and power.
- Connect your new modem to the coax wall outlet. Connect your Wi-Fi router (or computer) to the modem via Ethernet. Power on the modem and wait for it to initialize (5–15 minutes).
- Call Optimum at 1-866-200-7273 or use the Optimum app to activate the modem using its MAC address. Have your account number ready.
- Return the rented Smart Router to an Optimum store. Keep your return receipt — Optimum charges for unreturned equipment.
- Run a speed test immediately after activation to verify your plan speeds are being delivered.
Saving Money by Eliminating the Optimum Rental Fee
The $10/month Smart Router rental adds up to $120/year. A DOCSIS 3.1 modem like the ARRIS SURFboard SB8200 costs about $120 new — meaning it pays for itself in exactly one year. After that, every month is pure savings. Over a 3-year period, you save roughly $240 compared to continuous rental. Over 5 years the savings exceed $480.
Even the Motorola MB7621 at ~$60 — suitable for Optimum's 300 Mbps plan — pays for itself in just 6 months. The math strongly favors buying for anyone who plans to stay with Optimum for more than a year. The only scenario where rental makes sense is if you expect to switch providers within the next 6 months, or if you simply prefer Optimum handling all modem-related troubleshooting calls. For everyone else, owning your modem is the financially rational choice.
Frequently Asked Questions
Does Optimum allow you to use your own modem?
Yes — Optimum allows customer-owned modems on their cable (HFC) service. You save $10/month on the Smart Router rental fee. Note that Optimum fiber (FTTP) does not use a cable modem — the ONT provided by Optimum handles that function and cannot be replaced by a third-party device.
What DOCSIS version does Optimum use?
Optimum's cable network supports DOCSIS 3.0 and DOCSIS 3.1. Their 1 Gbps plan requires a DOCSIS 3.1 modem. For plans at 300 Mbps or below, a DOCSIS 3.0 modem with adequate channel bonding works fine.
How do I activate my own modem on Optimum?
Call Optimum at 1-866-200-7273 with your modem's MAC address ready. Alternatively, use the Optimum app or visit optimum.net/activate. Have your account number handy. Return the rented Smart Router to an Optimum store to stop rental charges.