Used 2021 GMC Sierra 2500HD for Sale nearDallas, TX

How much does the 2021 GMC Sierra 2500HD cost?

Prices have softened 5.93% compared to this time last year, making it a favorable time to shop this model year.

There are 1,925 listings available, which suggests a healthy amount of inventory to compare.

Is the 2021 GMC Sierra 2500HD a good car?

Yes — the 5/5 user rating points to strong owner satisfaction. The 2021 Sierra 2500HD stands out as a heavy-duty pickup that leans more upscale than many rivals, with more trim levels than the related Silverado 2500HD and a broader range of upscale options and features. It also gives you the kind of capability you expect from a three-quarter-ton truck, while offering amenities such as Bluetooth, Android Auto, Apple CarPlay, and a Wi-Fi hotspot. With 30.9% of listings marked as good or great deals, you have some room to shop selectively.

Is the 2021 GMC Sierra 2500HD reliable?

Owners rate it 5/5, a strong signal of long-term satisfaction.

The 2021 Sierra 2500HD is described as a capable heavy-duty truck with upscale features, but you should still pay close attention to known problem areas. The overview points to issues such as check engine lights tied to diesel particulate filters or emissions sensors, sluggish infotainment responses, rough or delayed shifts, electrical glitches, MultiPro tailgate flaws, and faulty trailer brake controllers. That means a careful pre-purchase inspection matters, especially if you plan to keep the truck for demanding towing or long-term use.

What should I look for when buying a used 2021 GMC Sierra 2500HD?

Accident-free inventory is solid at 77.8% — always verify the vehicle history report.

You should prioritize a history report first, then focus your inspection on signs of prior damage, repair quality, and maintenance consistency. Pay extra attention to the truck’s electronics, transmission behavior, tailgate operation, and any warning lights or trailering-system issues. Because this model can be expensive even used, condition should matter as much as trim level or equipment.

Is now a good time to buy a used 2021 GMC Sierra 2500HD?

This is a moderate market, so you can buy now if the truck checks your boxes, but selective shoppers still have leverage.

• Deal availability: 30.9% of listings are priced as good or great deals.
• Inventory: There are 1,925 listings available.
• Price trend: Prices have softened 5.93% compared with last year.
• Clean inventory: 77.8% of listings are accident-free.

If you find a listing below $49,717, that's toward the low end of the year-round range and worth acting on quickly.

What is the 2021 GMC Sierra 2500HD's resale value?

The current average of $49,722 sits slightly below last year's $52,859.

That price movement suggests the market has cooled a bit, which can help you buy more carefully today but may also limit short-term upside if you plan to resell soon. For a future seller, the current trend means you should expect value to depend heavily on condition, mileage, and equipment rather than assuming appreciation. Well-kept trucks with desirable features and clean history should still draw stronger interest than average examples.

Vehicles with strong owner satisfaction ratings, like this model year's 5/5, tend to retain buyer demand, which supports resale value over time.

Should I buy a 2021 GMC Sierra 2500HD or consider a different year?

If you're weighing the 2021 against nearby model years, here's how to think about it:

Choose the 2021 if:

• 30.9% of listings are priced as good or great deals.
• Accident-free inventory is solid at 77.8% — always verify the vehicle history report.
• Price trend: Prices have softened 5.93% compared with last year.
• Owners rate it 5/5 — a strong satisfaction signal.

Consider the 2020 if:

• At $48,344, the 2020 costs less than the current year's $49,722 average.
• It emphasizes Denali luxury with strong capability and plenty of cargo space.

Consider the 2022 if:

• At $50,616, the 2022 costs more than the current year's $49,722 average.
• It adds broader everyday versatility with more attention to off-road ability and trailering tech.

The bottom line: The 2021 is the best fit if you want the strongest mix of upscale features, broad configuration choice, and a still-reasonable market position. If price matters most, the 2020 is the better value path, while the 2022 makes sense if you want the newer feature mix and are willing to pay more.

How does the 2021 GMC Sierra 2500HD compare to the 2021 Ford F-250 Super Duty?

Read our full side-by-side expert comparison here.

These recommendations are based on CarGurus' proprietary market data from October 21, 2026, CarGurus experts' opinions, and generative AI.