Used 2020 GMC Sierra 3500HD for SaleNationwide

How much does the 2020 GMC Sierra 3500HD cost?

Prices have softened 7.87% compared to this time last year, making it a favorable time to shop this model year.

There are 446 listings available, which gives you a meaningful amount of inventory to compare.

If you find a listing below $50,329.50, that's toward the low end of the year-round range and worth acting on quickly.

Is the 2020 GMC Sierra 3500HD a good car?

Yes — the 2020 GMC Sierra 3500HD earns a 5/5 user rating, which points to very strong owner satisfaction.

Owners consistently praise its heavy-duty performance, especially when pulling heavy loads, and they also describe it as comfortable and well-built. The review summary also highlights a strong track record compared with competitors like Ford and Ram, which matters if you want a truck that feels proven in real-world use. In practical terms, that makes it a strong fit if you need serious towing and hauling capability with enough comfort to handle regular driving, not just job-site duty.

28.0% of listings are priced as good or great deals, so you still have room to shop selectively.

Is the 2020 GMC Sierra 3500HD reliable?

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

The review summary points to a truck that feels dependable, trouble-free, and well-built, with owners especially confident in its ability to handle demanding work over time. That kind of feedback is encouraging if you want a heavy-duty pickup you can count on for towing and hauling without constant second-guessing.

For used buyers, the main long-term ownership risk is less about the truck’s core capability and more about finding one that has been maintained properly and not overworked.

What should I look for when buying a used 2020 GMC Sierra 3500HD?

At 73.8% accident-free, a meaningful share of listings has prior incidents — history verification is especially important.

You should start with a vehicle history report so you can separate clean trucks from ones with accident or damage records. After that, prioritize a thorough inspection of the frame, suspension, towing hardware, and interior wear, since heavy-duty trucks are often used hard. You should also focus on overall condition and maintenance evidence, because a well-kept truck is especially important in this segment.

Is now a good time to buy a used 2020 GMC Sierra 3500HD?

This looks like a moderate, selective buyer’s market, so you can shop carefully without expecting every listing to be a bargain.

• Deal availability: 28.0% of listings are priced as good or great deals.
• Inventory: There are 446 listings available.
• Price trend: Prices have softened 7.87% compared with last year.
• Clean inventory: 73.8% of listings are accident-free.

If you find a listing below $50,329.50, that's toward the low end of the year-round range and worth acting on quickly.

What is the 2020 GMC Sierra 3500HD's resale value?

The current average of $50,834 sits slightly below last year's $55,175.

That price movement suggests the market has cooled enough to give you better entry pricing now, but it also means future sellers may not see the same level of appreciation they would have a year ago. If you buy well and keep the truck in strong condition, you can help protect value, especially because heavy-duty trucks with broad appeal tend to stay relevant with work-focused buyers. The biggest resale advantage will come from choosing a clean, well-maintained example with the right configuration for demand.

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 2020 GMC Sierra 3500HD or consider a different year?

If you're weighing the 2020 against nearby model years, here's how to think about it:

Choose the 2020 if:

• 28.0% of listings are priced as good or great deals.
• At 73.8% accident-free, a meaningful share of listings has prior incidents — history verification is especially important.
• Price trend: Prices have softened 7.87% compared with last year.
• Owners rate it 5/5 — a strong satisfaction signal.

The bottom line:

If you want the redesigned heavy-duty Sierra with strong owner approval and a softer price than last year, the 2020 is the primary year to target. If you are especially price-sensitive, you can also compare nearby years to see whether a lower asking price outweighs the 2020’s stronger market position and owner satisfaction.

These recommendations are based on CarGurus' proprietary market data from August 28, 2026, CarGurus experts' opinions, and generative AI.