How much does the 2020 GMC Sierra 3500HD cost?

Prices have softened 7.77% compared to this time last year, making it a favorable time to shop this model year.

There are 448 listings available, which gives you a meaningful pool to compare prices and equipment.

If you find a listing below $50,338.74, 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 5/5 user rating points to strong owner satisfaction. Owners consistently praise its heavy-duty performance, especially when pulling heavy loads, along with its comfortable, well-built feel. The overview also shows why it fits your needs if you want serious towing and hauling ability with a wide spread of cab, bed, axle, and trim choices. With 29.0% of listings marked as good or great deals, 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 owner feedback also points to a truck that feels dependable and trouble-free in the ways that matter most to heavy-duty buyers, especially when it comes to hard work and sustained use. That said, used heavy-duty ownership still depends on how the truck was maintained and used, so you should pay close attention to service history and wear from towing or hauling.

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

At 72.1% 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 those with prior damage. Then prioritize a thorough inspection of the frame, suspension, bed, towing hardware, and interior wear, since heavy-duty use can leave behind clues even when the truck looks good at first glance. Focus on condition and maintenance records, especially if you plan to use the truck for demanding work.

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

This is a moderate market for selective buyers, so you can shop with some leverage if you know what you want.

• Deal availability: 29.0% of listings are priced as good or great deals.
• Inventory: There are 448 listings available.
• Price trend: Prices have softened 7.77% compared with last year.
• Clean inventory: 72.1% of listings are accident-free.

If you find a listing below $50,338.74, 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 $50,874 sits slightly below last year's $55,162.

That softer pricing suggests the truck has already moved through a meaningful portion of its depreciation curve, which can help future sellers if demand stays steady. Because the model still draws buyers who want serious towing and hauling capability, well-kept examples should remain easier to position than trucks with unclear history or heavy wear. Strong condition and documented maintenance will matter most if you want to protect your return later.

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:

• 29.0% of listings are priced as good or great deals.
• At 72.1% accident-free, a meaningful share of listings has prior incidents — history verification is especially important.
• Price trend: Prices have softened 7.77% 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 a year ago, the 2020 is the primary year to target. If you are especially price-sensitive, you may want to compare nearby years and focus on the cleanest, best-maintained truck rather than chasing the newest badge alone.

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