Used 2021 GMC Sierra 1500 for Sale near Colorado

How much does the 2021 GMC Sierra 1500 cost?

Prices have softened 9.24% compared to this time last year, making it a favorable time to shop this model year.

There are 7,151 listings available, which gives you a healthy pool to compare prices and equipment.

Is the 2021 GMC Sierra 1500 a good car?

Yes — the 2021 GMC Sierra 1500 earns a 4.9/5 user rating, and our experts rate it 5.67/10.

The standout strength is Performance at 9/10.

Owners repeatedly praise its luxurious feel, comfort, advanced technology, and strong engine performance. The Sierra also gets credit for offering great value for money, which matters if you want a full-size truck that feels more upscale than basic work-truck transportation.

The trade-offs are clear: the technology is described as outdated, and the interior materials feel cheap. The overview also points to a truck that works best when you choose the right configuration, especially if you want the Duramax diesel rather than the underwhelming base engine.

The Sierra 1500 is a flexible fit if you want multiple body styles and powertrain choices in a full-size pickup, but it rewards shoppers who are selective about trim and engine. Good and great deals account for 34.6% of listings, so there is some room to shop carefully.

Is the 2021 GMC Sierra 1500 reliable?

Owners rate it 4.9/5, a strong signal of long-term satisfaction.

The owner feedback also points to a truck that feels dependable, trouble-free, and worth counting on over time, with many reviewers emphasizing its strong overall value and lasting appeal. On the road, the diesel powertrain is described as pairing smoothly with the transmission, and the truck’s easy-to-use 4WD system adds to its everyday confidence.

The diesel engine is also framed as a bargain relative to competing diesel trucks, which can help reduce the sting of ownership if you choose that setup. For used buyers, the main long-term risk is that the Sierra’s appeal depends heavily on configuration, so a poorly equipped or neglected example may not deliver the same satisfaction as a well-kept one.

What should I look for when buying a used 2021 GMC Sierra 1500?

Accident-free inventory is solid at 79.3% — always verify the vehicle history report.

You should still run a history report on any truck you’re considering, because accident-free listings are common but not guaranteed. Prioritize a pre-purchase inspection that focuses on wear, electronics, and any signs that the truck has been used hard. Pay close attention to condition, because the Sierra can vary a lot depending on trim, options, and how it was driven.

Key things to evaluate:

• Trim level: The Denali trim is the upscale choice, while the AT4 adds off-road-oriented hardware such as a suspension lift, skid plates, a locking rear differential, and unique design details. The base truck can feel sparse, and some desirable safety features are not standard even on higher trims.
• Powertrain: The Duramax 3.0-liter turbodiesel six-cylinder is the standout choice, with 277 horsepower and 460 pound-feet of torque. It pairs with a 10-speed automatic and is described as the best value in the lineup unless you specifically want a V8.
• Safety package: Forward collision warning, front pedestrian braking, and automatic emergency braking are available, while blind-spot warning and rear cross-traffic warning come on Denali and are optional on other trims. Lane-departure warning, lane-keeping assistance, and a Safety Alert Seat are also available depending on trim.
• Infotainment: You can get a 7-inch or 8-inch touchscreen, and wireless Apple CarPlay and Android Auto come standard. The truck also offers a navigation system, SiriusXM satellite radio, a 4G LTE WiFi hotspot, and available camera-based upgrades.
• Fuel efficiency: The Duramax diesel is rated at 24 mpg in combined driving, and the test truck averaged 21.1 mpg in mixed real-world use.

Which 2021 GMC Sierra 1500 trim should I buy?

The 2021 GMC Sierra 1500 is offered in 2 trim levels: Elevation, AT4.

Here's the short version:

• Elevation: This is the trim most buyers should strongly consider if you want a custom appearance and room to add options without pushing the price too high. It can help you keep the truck around $43,000 while still leaving room to climb if you want more equipment.
• AT4: This is the better pick if you want the more rugged, off-road-ready personality. It adds a factory lift, off-road suspension, skid plates, a locking rear differential, and other capability-focused details, and it pairs especially well with the Duramax diesel.

The safety content also notes that some driver-assistance features remain optional rather than standard, even on higher trims.

Is now a good time to buy a used 2021 GMC Sierra 1500?

This is a moderate market for selective buyers, so you can shop with some leverage if you’re patient.

• Deal availability: 34.6% of listings are priced as good or great deals.
• Inventory: There are 7,151 listings available.
• Price trend: Prices have softened 9.24% compared with last year.
• Clean inventory: 79.3% of listings are accident-free.

If you find a listing below $34,534, that's toward the low end of the year-round range and worth acting on quickly.

What is the 2021 GMC Sierra 1500's resale value?

The current average of $34,534 sits slightly below last year's $38,050.

That decline suggests the market has already adjusted downward, which can help you buy at a more favorable entry point today. For a future seller, it also means you should expect resale value to depend heavily on condition, mileage, and configuration rather than just the badge on the grille.

Trucks with desirable equipment and strong upkeep should hold up better than stripped or neglected examples. The diesel, higher-demand trims, and clean history should all help support future demand.

Vehicles with strong owner satisfaction ratings, like this model year's 4.9/5, tend to retain buyer demand, which supports resale value over time.

Is the 2021 GMC Sierra 1500 safe?

The 2021 GMC Sierra 1500 earns a four-star overall rating from NHTSA due to four-star protection levels for the driver and front passenger in the frontal-impact test. IIHS rates the truck Marginal in the small-overlap frontal-impact test and gives its headlights a Poor rating.

It earns a 4/10 safety score from our experts.

The Sierra’s safety equipment is uneven. Forward collision warning, front pedestrian braking, and automatic emergency braking are available, but they are not standard across the lineup. Blind-spot warning and rear cross-traffic warning are included on Denali and optional on other trims, while lane-departure warning, lane-keeping assistance, and a Safety Alert Seat are also available depending on trim.

That mix means you should pay close attention to the exact truck you’re considering, because safety content varies by trim and some important features may be missing. The IIHS results also point to a real weakness in crash protection and headlight performance, so safety should be a major part of your shopping checklist.

Should I buy a 2021 GMC Sierra 1500 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:

• 34.6% of listings are priced as good or great deals.
• Accident-free inventory is solid at 79.3% — always verify the vehicle history report.
• Price trend: Prices have softened 9.24% compared with last year.
• Owners rate it 4.9/5 — a strong satisfaction signal.
• It offers a flexible mix of body styles, powertrains, and distinctive GMC styling.

Consider the 2020 if:

• At $32,965, the 2020 costs less than the current year's $34,534 average.
• It emphasizes everyday usability and comfort with useful cargo and convenience features.

Consider the 2022 if:

• At $41,360, the 2022 costs more than the current year's $34,534 average.
• It brings a major redesign with a more upscale interior and standard high-end technology.

The bottom line: If you want the best balance of price, inventory, and owner satisfaction, the 2021 is the sensible target. If you’re especially price-sensitive, the 2020 can save you money, while the 2022 makes sense if you want the newer redesign and are willing to pay more for it.

These recommendations are based on CarGurus' proprietary market data from October 13, 2026, CarGurus experts' opinions, and generative AI.