2020 Ram 2500 accessories range from bed liners and tonneau covers to side steps, hitch hardware, and lighting, but the right choice depends on how your specific truck was built. A 2020 Ram 2500 can have a short or long bed, a RamBox cargo system or none, and factory fifth-wheel/gooseneck prep or none. Each of those choices changes what will bolt on and what won’t.

This guide covers what to check first, which accessory categories matter most on this truck, and how to avoid the fitment mistakes that lead to returns.

Key Facts at a Glance

• The 2020 Ram 2500 belongs to Ram’s fifth-generation heavy-duty lineup, which Mopar supported with more than 170 products at the 2019 launch.
• Bed length, RamBox, and the factory 5th-Wheel/Gooseneck Prep Group are the details that most often decide whether an accessory fits.
• Published maximum towing figures for the 2020 model vary from source to source, so trust your door sticker and owner’s manual over a product listing.
• Mopar reviews its affiliated accessories for fitment, but each brand guarantees its own product.
• Owners report that traditional fifth-wheel hitches can clash with RamBox storage bins. Verify before you buy.
• A factory option may already solve the problem you’re shopping for.

Why Fitment Matters More on a Heavy-Duty Ram

A Ram 2500 isn’t one truck. It’s a family of configurations: regular, crew, and Mega Cab bodies, short and long beds, gas and diesel engines, and a long list of factory options.

Accessory retailers often group the whole 2019–2024 run together, which is helpful for browsing and misleading for buying. A listing that says “fits Ram 2500” tells you the brand and generation. It doesn’t tell you whether your truck has RamBox, a factory rail kit, or a spray-in liner already installed.

Retailers also label the short bed differently than Ram does. Ram specs it as 6’4″, while accessory catalogs commonly sort tonneau covers under “6-1/2 foot bed,” with and without RamBox. Read the fine print, not just the headline.

Model-year grouping causes its own confusion. The 2020 truck shares its generation with the 2019 and later models, so many parts carry over, and Mopar’s parts site lists 2019 and 2020 trucks separately by trim and engine. Don’t assume a part listed for a 2019 or 2022 truck fits yours just because it’s the same generation. Confirm it against the 2020 listing, or ask the seller to confirm in writing.

The fix is simple. Pull your window sticker or build sheet, or ask a Ram dealer’s parts department to look up your VIN, and write down your cab, bed length, and options before you shop.

Factory Options That Change What You Can Buy

Several available options on the 2020 Ram 2500 directly affect accessory choices:

• RamBox Cargo Management System: two lockable, drainable bins built into the bedsides, with LED lighting, a 115-volt outlet, and key-fob access.
• 5th-Wheel/Gooseneck Prep Group: a factory rear-axle crossmember with integrated mounting hardware for in-bed hitches.
• Auto-Level rear air suspension: adjusts to load changes, which matters when you add heavy accessories or tow.
• Power running boards: they deploy when a door opens, so a second set of steps would be redundant.

These descriptions come from Ram-sourced dealer content, so confirm what your own truck has. Used trucks in particular vary, and listings sometimes list options like a spray-in bedliner or a prep group right in the equipment list.

Bed Protection and Tonneau Covers

The bed is where most owners start. Mopar’s launch catalog for the 2019 Ram HD included bed liners, bed extenders, cargo ramps, toolboxes, and tonneau covers, and aftermarket brands cover the same ground with more variety.

Before buying a liner, check whether your truck already has a factory spray-in liner. Before buying a tonneau cover, check the bed and the RamBox.

RamBox matters here. One retailer Q&A on a 2019 Ram 2500 noted that a particular retractable cover wasn’t made for the 6-1/2 foot bed with RamBox, and pointed to a different model from the same brand that was. The brand was the same. The fitment wasn’t.

Towing setups add another layer. A separate retailer answer for a 2020 short-bed truck with the factory rail kit and an OEM-style fifth-wheel hitch suggested a retractable hard cover to hide the hitch. Owners on Ram forums also say a roll-up cover can let you mount a fifth-wheel hitch without removing the whole cover. That’s owner experience, not a spec, so check the cover’s clearance for your hitch.

Towing Hardware and the Prep Group

If you tow with a fifth wheel or gooseneck, the factory prep group is the biggest single factor in your accessory options. It gives hitch makers a standard mounting system to build around.

Trucks without it aren’t stuck. Aftermarket underbed gooseneck hitches exist, and retailer Q&A pages show owners asking exactly what “without factory prep” means before buying one. But the installation is different, so match the hitch to your truck’s setup.

Two cautions apply.

First, a hitch rating isn’t your truck’s rating. A hitch rated for 35,000 pounds doesn’t make a Ram 2500 a 35,000-pound tow vehicle. Published maximum towing figures for the 2020 Ram 2500 range from roughly 19,680 to 19,980 pounds depending on the source, and those numbers vary with engine, axle, and equipment. Use your door-jamb ratings and owner’s manual. Our Ram trucks towing guide explains how to read the numbers that apply to you.

Second, RamBox and fifth-wheel hitches don’t always mix. Owners on Ram forums report that traditional fifth-wheel hitches can hit the inner sides of the RamBox, while gooseneck hitches use a center ball and avoid the problem. Forum posts aren’t engineering data, but the question comes up often enough in retailer Q&A that it’s worth checking with the hitch maker before you commit.

Mopar also offered a fifth-wheel hitch, gooseneck ball kit, and trailer camera for the 2019 HD launch, so factory-matched options exist alongside aftermarket ones.

Steps, Running Boards, and Cab Access

The 2500 sits high. Steps make a real difference for kids, passengers, and anyone climbing in and out all day.

Mopar sells side-step components separately, including left and right steps, bracket kits, end caps, and step pads, according to its parts catalog. That helps if you’re repairing a damaged step instead of replacing the whole system.

If your truck already has factory power running boards, adding another set doesn’t make much sense. If it doesn’t, compare fixed steps and tubular bars on cab coverage, mounting method, and ground clearance if you go off-road.

For more detail, see our guides to Mopar running boards and Ram truck step bars.

Interior, Lighting, and Everyday Add-Ons

Not every worthwhile accessory is dramatic. Mopar’s 2019 HD launch lineup included waterproof all-weather floor mats, stainless sill guards, a wireless smartphone charger, heavy-duty splash guards, and Katzkin leather seats. Mopar’s current catalog for the 2020 Ram 2500 organizes accessories into audio/video, carriers and cargo hauling, exterior, interior, lifestyle and off-road, lighting and electrical, and vehicle care.

For lighting, Mopar’s show truck used a bed-mounted Ram Bar topped with five LED off-road lights. That’s a good example of a popular add-on that’s easy to get wrong. Wiring matters more than the light. Some 2020 trucks have factory auxiliary switches, and some don’t, so check yours before splicing into anything.

Floor mats and liners are a fitment issue too. Order by cab style (regular, crew, or Mega Cab), not just by model name.

Accessories need upkeep, too. A bed mat or liner can trap moisture and debris underneath it, so lift it occasionally, rinse the bed, and make sure the drains aren’t blocked. Check step brackets and hitch hardware for loose bolts after the first few hundred miles, and again after heavy towing. Small checks like these cost minutes, and they catch problems before they turn into rust or rattles.

If you’re upgrading a Cummins-powered truck, our Cummins diesel accessories guide covers tuning, lifts, and towing gear in more depth. For floor, bed, and storage basics, start with our overview of Ram truck accessories.

OEM, Mopar-Reviewed, or Aftermarket?

There’s no universal winner. Mopar parts are built for Ram vehicles, and its affiliated-accessory program is reviewed by Mopar for fitment, though each brand guarantees its own product. Aftermarket brands offer more variety and specialty gear. Used parts can save money, but you’ll want to confirm that they match your configuration.

This table summarizes what to verify, by category:

The pattern is consistent: the part’s name rarely causes the problem. The configuration does. Our guide to aftermarket Ram truck parts goes deeper on choosing the right fit.

What Owners Say, and How to Verify It

Owner forums are valuable for spotting recurring questions: RamBox clearance, cover compatibility, hitch mounting. They aren’t proof. One owner’s setup doesn’t tell you what your truck needs.

Use a simple routine before you order:

1. Find your build sheet, window sticker, or VIN-based options list.
2. Note cab style, bed length, RamBox, and whether you have the prep group.
3. Read the fitment notes, not just the title.
4. Ask the seller or manufacturer to confirm fitment for your exact options.
5. For anything towing-related, compare against your door-jamb ratings.

You can also browse Mopar’s online catalog for the 2020 Ram 2500 and Mopar’s affiliated accessories. For background on what Mopar offered at launch, see Stellantis’s 2019 Ram Heavy Duty Mopar announcement. Our broader guide to Ram 2500 accessories covers general categories across model years.

The Takeaway

The best 2020 Ram 2500 accessories aren’t the most popular ones. They’re the ones that match your cab, bed, and factory options, and solve a problem you actually have.

Start with your build sheet. Settle RamBox and prep-group questions before buying covers or hitches. And treat every towing number as a limit, not a target.