Used 2021 GMC Sierra 1500 for Sale nearSlidell, LA

How much does the 2021 GMC Sierra 1500 cost?

Prices have softened 8.94% compared to this time last year, making it a favorable time to shop this model year.

There are 6,680 listings available, which suggests you have a healthy amount of inventory to compare.

If you find a listing below $35,401.43, that's toward the low end of the year-round range and worth acting on quickly.

Is the 2021 GMC Sierra 1500 a good car?

Yes — the 2021 GMC Sierra 1500 earns a 4.9/5 user rating and a 5.67/10 expert rating. The standout strength is Performance at 9/10.

Owners consistently praise its luxurious features, strong engine performance, advanced technology, and comfortable interior. The truck also gets credit for offering great value for money, with many reviewers feeling it stands out in its class.

The trade-offs are familiar: the technology can feel outdated, the interior materials feel cheap, and the base engine is underwhelming. Even so, the Sierra’s mix of multiple body styles, multiple powertrain options, and easy-to-use technology makes it appealing if you want a full-size pickup that can be configured for work, commuting, or a more upscale setup.

Only 28.1% of listings are priced as good or great deals, so the market rewards patience and comparison shopping.

Is the 2021 GMC Sierra 1500 reliable?

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

The owner feedback points to a truck that feels dependable, with reviewers highlighting strong performance, comfort, and value over time. The diesel setup also comes across as a smart long-term choice because it is described as an affordable engine option that delivers strong torque and efficient highway use.

The test-drive notes reinforce that impression by describing the 10-speed automatic as flawlessly adept at choosing gears and keeping the engine in its torque band. The Duramax diesel is also presented as a bargain relative to competing diesel trucks.

For used buyers, the main long-term ownership risk is that the Sierra can still nickel-and-dime you with options and subscriptions, so condition and equipment matter as much as mileage.

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

Accident-free inventory is solid at 80.6% — always verify the vehicle history report.

You should still run a history report on any truck you’re considering, even if the listing looks clean. Prioritize a pre-purchase inspection that checks the cabin, electronics, and any added equipment, since the Sierra’s appeal depends heavily on how it was optioned. Focus on overall condition and feature content, because the difference between a basic truck and a well-equipped one is significant here.

Key things to evaluate:

• Trim level: The Denali trim level is the upscale choice, while the AT4 adds off-road-ready hardware and distinctive styling. The base truck can feel sparse, so feature gaps matter a lot if you want a more premium experience.
• Powertrain: The Duramax 3.0-liter turbodiesel six-cylinder is the standout choice, with 277 horsepower and 460 pound-feet of torque. The 10-speed automatic and available 4WD system help it feel strong and flexible, while the base engine is described as underwhelming.
• 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 system also includes SiriusXM satellite radio, a 4G LTE WiFi hotspot, and a navigation system, with the optional Technology Package adding a 15-inch head-up display and an 8-inch driver information display.
• Fuel efficiency: The Duramax diesel is rated at 24 mpg in combined driving, and the test truck averaged 21.1 mpg in mixed conditions.

Which 2021 GMC Sierra 1500 trim should I buy?

The 2021 GMC Sierra 1500 is offered in 3 trim levels: Elevation, AT4, Denali.

Here's the short version:

• Elevation: This is the best-value trim to consider if you want to keep costs in check while still getting a custom appearance and access to a wide range of options. It can stay near $43,000 if you keep it simple, but it also leaves room to climb much higher with extras.
• AT4: This is the right pick if you want the most rugged personality in the lineup. It adds a 2-inch suspension lift, off-road suspension, skid plates, a locking rear differential, and distinctive off-road styling, making it the most capability-focused choice.
• Denali: This is the luxury-oriented trim, with the most upscale presentation and the strongest premium appeal. It suits you best if you want the Sierra’s most boast-worthy version and are willing to pay for it.

Safety features such as blind-spot warning and rear cross-traffic warning are standard on Denali and optional on other trims.

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

This looks like a moderate, selective buyer’s market, so you can shop carefully and still find opportunities.

• Deal availability: 28.1% of listings are priced as good or great deals.
• Inventory: There are 6,680 listings available.
• Price trend: Prices have softened 8.94% compared with last year.
• Clean inventory: 80.6% of listings are accident-free.

If you find a listing below $35,401.43, 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 $35,389 sits slightly below last year's $38,862.

That price movement suggests the Sierra has already absorbed some depreciation, which can help future sellers if they buy at the right point. A softer market today may also make it easier for you to find a cleaner truck at a more realistic price, which can support resale later if you avoid overpaying now.

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?

It earns four-star ratings in frontal crash and rollover, and five-star ratings in all other NHTSA tests.

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

The Sierra’s safety equipment is uneven for a premium-branded truck. Forward collision warning, front pedestrian braking, and automatic emergency braking are available, while blind-spot warning and rear cross-traffic warning are standard on Denali and optional on other trims. Lane-departure warning, lane-keeping assistance, and a Safety Alert Seat are also available depending on trim, and adaptive cruise control is offered on SLT, AT4, and Denali.

The weak spots are important to note: IIHS gives the truck a Marginal result for the front passenger in the small-overlap frontal test, a Poor headlight rating, and Marginal LATCH accessibility. If safety is a top priority, you should pay close attention to how the truck is equipped and not assume the premium badge means premium protection.

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:

• 28.1% of listings are priced as good or great deals.
• Accident-free inventory is solid at 80.6% — always verify the vehicle history report.
• Price trend: Prices have softened 8.94% compared with last year.
• Owners rate it 4.9/5 — a strong satisfaction signal.
• This year balances strong performance, useful tech, and multiple powertrain choices.

Consider the 2020 if:

• At $33,608, the 2020 costs less than the current year's $35,389 average.
• It blends SUV-like comfort with practical truck utility.

Consider the 2022 if:

• At $42,558, the 2022 costs more than the current year's $35,389 average.
• It brings a major redesign with more luxury, better tech, and new trims.

The bottom line: If you want the best balance of price, satisfaction, and available inventory, the 2021 is the sensible target. If you’re shopping on a tighter budget, the 2020 gives you a lower entry point, while the 2022 makes sense only if you want the newer design and are willing to pay more for it.

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