Used 2021 GMC Sierra 1500 for Sale nearReading, PA

How much does the 2021 GMC Sierra 1500 cost?

Prices have softened 9.23% compared to this time last year, making it a favorable time to shop this model year.

There are 7,101 listings available, which suggests solid inventory availability.

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 feel, comfort, advanced technology, and strong engine performance. The truck also gets credit for offering good value for money, which lines up with its flexible mix of body styles and powertrain choices.

The trade-offs are clear: the technology can feel outdated, the interior materials can feel cheap, and the base engine is underwhelming. That means you’ll be happiest if you shop the right configuration rather than assuming every version delivers the same experience.

The Sierra 1500 is especially appealing if you want a full-size pickup that can be tailored to work, commuting, or more upscale use. Good and great deals account for 34.6% of listings, which gives you 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.

Reviewers describe it as dependable, with praise centered on its strong performance, comfort, and overall value. The ownership feedback also points to a truck that many drivers feel good about keeping for the long haul.

The expert drive notes reinforce that impression by describing the Duramax diesel as a bargain and praising the transmission for choosing gears smoothly and keeping the engine in its torque band. That kind of powertrain behavior usually matters a lot in day-to-day dependability.

The diesel option also helps the Sierra feel like a smart long-term choice if you want capability without giving up efficiency. For used buyers, the main ownership risk is ending up with a poorly maintained truck or one that was optioned in a way that doesn’t match your needs.

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, even if it looks clean on the lot. A pre-purchase inspection matters too, especially on higher-mileage examples or trucks that were used for towing, hauling, or off-road driving. Focus on condition, maintenance records, and whether the equipment on the truck matches how you plan to use it.

Key things to evaluate:

• Trim level: The Sierra’s styling and upscale Denali trim are key differentiators, while the AT4 adds an off-road-ready setup with a 2-inch suspension lift, skid plates, a locking rear differential, and unique design details. The base truck is also described as lacking some of the more premium feel you may want, so trim choice matters a lot.
• Powertrain: The Duramax 3.0-liter turbodiesel six-cylinder is the standout engine, with 277 horsepower and 460 pound-feet of torque, plus a 10-speed automatic transmission. It’s described as the best fit 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 the 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: The Sierra offers 7-inch and 8-inch touchscreen displays, wireless Apple CarPlay and Android Auto, SiriusXM satellite radio, a 4G LTE WiFi hotspot, and navigation. The available Technology Package adds a surround-view camera, trailer- and bed-view cameras, a rear camera mirror, 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 3 trim levels: Elevation, AT4, Denali.

Here's the short version:

• Elevation: This is the trim most buyers should strongly 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 around $43,000 if you keep it restrained, but it can also climb quickly with extras.
• AT4: This is the best fit if you want the rugged, off-road-ready version with the 2-inch suspension lift, off-road suspension, skid plates, and locking rear differential. It also pairs especially well with the Duramax diesel, which the test-drive data treats as the Sierra’s sweet spot.
• Denali: This is the upscale choice if you want the most premium styling and the most boast-worthy version of the Sierra. It adds the luxury angle, but the safety content also makes clear that some driver-assistance features remain optional rather than standard.

Safety-package note: blind-spot warning and rear cross-traffic warning are standard on Denali, but optional on other 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 carefully and still find value.

• Deal availability: 34.6% of listings are priced as good or great deals.
• Inventory: There are 7,101 listings available.
• Price trend: Prices have softened 9.23% compared with last year.
• Clean inventory: 79.3% of listings are accident-free.

If you find a listing below $34,653, 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 $34,653 sits slightly below last year's $38,176.

That decline suggests the market has already adjusted downward, which can help you as a buyer but may limit upside if you plan to resell soon. If you buy at the right price, you reduce the chance of taking a bigger depreciation hit later.

For a future seller, the key is to own a truck that still feels desirable in the used market. Well-equipped versions with the right powertrain and strong condition should hold up better than stripped or poorly maintained 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 overall from NHTSA, 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. 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.

The main caveat is the crash-test performance itself. IIHS rates the front-passenger small-overlap frontal result as Marginal, gives the headlights a Poor rating, and rates LATCH anchor accessibility as Marginal.

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 9.23% compared with last year.
• Owners rate it 4.9/5 — a strong satisfaction signal.
• This year stands out for its flexible mix of body styles, powertrains, and the appealing Duramax diesel setup.

Consider the 2020 if:

• At $33,080, the 2020 costs less than the current year's $34,653 average.
• It emphasizes everyday usability, comfort, and utility-minded features.

Consider the 2022 if:

• At $41,641, the 2022 costs more than the current year's $34,653 average.
• It brings a major makeover with a bolder design, a more lavish interior, and standard high-end technology.

The bottom line: buy the 2021 if you want the best balance of price, inventory, and the Sierra’s strongest powertrain and trim mix. If you’re more price-sensitive, the 2020 is the easier entry point; if you want a more upscale truck and can spend more, the 2022 is the step up.

These recommendations are based on CarGurus' proprietary market data from October 6, 2026, CarGurus experts' opinions, and generative AI.