Used 2021 GMC Sierra 1500 for Sale nearSlidell, LA

How much does the 2021 GMC Sierra 1500 cost?

Prices have softened 8.92% compared to this time last year, making it a favorable time to shop this model year.

There are 6,733 listings available, which suggests solid inventory for comparison shopping.

Is the 2021 GMC Sierra 1500 a good car?

Yes — 4.9/5 from owners, and the expert rating is 5.67/10. The standout strength is Performance at 9/10.

Owners consistently praise the Sierra’s luxurious features, strong engine performance, advanced technology, and comfortable interior. The truck also gets credit for feeling like a good value for the money, which lines up with its broad appeal as a full-size pickup that can fit work and everyday use.

The trade-offs are clear: the technology can feel outdated, the interior materials can feel cheap, and the base engine is underwhelming. Even so, the Sierra’s mix of multiple body styles and multiple powertrain options makes it easy to tailor to your needs.

Good and great deals account for 31.5% of listings, so you have some room to shop selectively.

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 people feel good about living with over time, especially because they repeatedly mention dependable performance, comfort, and strong overall value. The expert test-drive notes also support that impression by describing the Duramax diesel and 10-speed automatic as a well-matched, confident combination.

The diesel option is the most cost-effective powertrain, which can help lower operating costs if it fits your driving needs. For used buyers, the main long-term ownership risk is that the Sierra can still nickel-and-dime you with options and features, so condition and equipment matter a lot.

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

Accident-free inventory is solid at 79.7% — always verify the vehicle history report.

You should still run a history report on any truck you’re considering, because accident-free listings are not the same as guaranteed trouble-free ownership. Prioritize a close inspection of the cabin, electronics, and any added packages, since the Sierra’s feature content varies a lot by trim and option set. It also makes sense to focus on how the truck was used, especially if you’re looking at higher-mileage examples or off-road-oriented versions.

Key things to evaluate:

• Trim level: The Denali trim level is the upscale choice, while the AT4 adds an off-road-ready setup with a 2-inch suspension lift, Rancho monotube shocks, skid plates, a two-speed Autotrac transfer case, a locking rear differential, and unique exterior details. The cabin can feel basic in places, and the base setup leaves some buyers wanting more refinement.
• Powertrain: The Duramax 3.0-liter turbodiesel six-cylinder makes 277 horsepower and 460 pound-feet of torque, and it pairs with a 10-speed automatic transmission. It is described as a bargain and a strong match for the truck’s character.
• 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 Sierras. Lane-departure warning, lane-keeping assistance, and a Safety Alert Seat are also available depending on trim.
• Infotainment: The Sierra offers a 7-inch or 8-inch touchscreen, wireless Apple CarPlay and Android Auto, SiriusXM satellite radio, a 4G LTE WiFi hotspot, and a navigation system. The available Technology Package adds a 15-inch head-up display and an 8-inch driver information display.
• Fuel efficiency: The Duramax diesel averaged 21.1 mpg in testing and is rated at 24 mpg in combined driving.

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 access to a wide range of options without letting the price run away. It can help you keep the truck around $43,000 while still leaving room to add equipment, making it the best-value path for many shoppers.
• AT4: This is the choice if you want the more rugged, off-road-focused setup. It adds the lifted suspension, off-road hardware, and distinctive design details, and it suits you best if you want capability and a more adventurous personality.

The safety content also notes that forward collision warning, front pedestrian braking, and automatic emergency braking are optional rather than standard, so check equipment carefully by trim.

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 with some leverage if you’re patient.

• Deal availability: 31.5% of listings are priced as good or great deals.
• Inventory: There are 6,733 listings available.
• Price trend: Prices have softened 8.92% compared with last year.
• Clean inventory: 79.7% of listings are accident-free.

If you find a listing below $35,149, 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 $35,149 sits slightly below last year's $38,591.

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 trim, condition, mileage, and equipment rather than just the badge alone.

Because the Sierra still draws strong owner satisfaction, well-kept examples should continue to attract buyers. Trucks with desirable powertrains and cleaner histories are likely to hold demand better than stripped or heavily used examples.

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 four-star ratings in frontal crash, and five-star ratings in all other NHTSA tests. The IIHS gives it a Marginal result for the front passenger in the small-overlap frontal test and a Poor headlight rating.

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

The Sierra’s safety equipment is more limited than you might expect 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 included on Denali and optional on other trims. Lane-departure warning, lane-keeping assistance, and a Safety Alert Seat are also available depending on trim.

The main caution is that the crash-test results are mixed, especially the IIHS findings. If safety is a top priority, you should pay close attention to the exact trim and option content rather than assuming every Sierra is equally equipped.

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:

• 31.5% of listings are priced as good or great deals.
• Accident-free inventory is solid at 79.7% — always verify the vehicle history report.
• Price trend: Prices have softened 8.92% compared with last year.
• Owners rate it 4.9/5 — a strong satisfaction signal.
• This year balances familiar capability with distinctive styling and multiple powertrain choices.

Consider the 2020 if:

• At $33,434, the 2020 costs less than the current year's $35,149 average.
• It feels more like a comfortable, utility-minded truck for everyday use.

Consider the 2022 if:

• At $42,152, the 2022 costs more than the current year's $35,149 average.
• It brings a major redesign with more luxury, more tech, and new high-end trims.

The bottom line: If you want the best balance of price, inventory, and owner satisfaction, the 2021 is the sensible pick. If your budget is tighter, the 2020 can save you money. If you want the newer design and are willing to pay more, the 2022 is the upgrade path.

These recommendations are based on CarGurus' proprietary market data from September 15, 2026, CarGurus experts' opinions, and generative AI.