by Amerisleep AS3 vs Costco (2026): Side-by-Side Comparison
One is a single mattress built to a specific feel. The other is a retailer stocking many brands. Here is how to decide.
The Amerisleep AS3 is the pick if you want a single, clearly specified medium-feel all-foam mattress with a 100-night trial, a 20-year warranty, and free shipping and returns. Costco is a retailer carrying many brands and compositions, so your trial, warranty, and return process depend on the specific mattress you choose there. If you already know you want a medium-feel all-foam bed and want the terms in writing from one maker, buy the AS3. If you want to browse multiple brands in person or online and compare side by side, start at Costco and check each product page for its own trial and warranty before you buy.
Amerisleep AS3
A medium-feel all-foam bed that Amerisleep builds to balance support and softness for every sleep position.
Saatva Classic
- 365-night home trial, which is longer than the AS3's 100 nights
- Lifetime warranty, which is longer than the AS3's 20-year warranty
- Free white-glove delivery with old-mattress removal
- Three comfort levels (Plush Soft, Luxury Firm, Firm) and two heights
- Innerspring build, so it will not isolate motion like an all-foam bed
- Not an all-foam option if you specifically want foam
- Comfort level choice adds a decision before you order
The Saatva Classic is the stronger pick on trial length and warranty length, and the in-home delivery with old-mattress removal is a real convenience. It is an innerspring mattress, so if you want an all-foam build like the AS3, it is a different category. Choose it when you want a longer trial, a lifetime warranty, and a traditional coil feel.
Amerisleep AS3 vs Costco: key specs
| Spec | Amerisleep AS3 | Costco (retailer) |
|---|---|---|
| What it is | Single all-foam mattress (AS3) | Retailer carrying many brands and compositions |
| Construction | All-foam with plant-based Bio-Pur | Varies: memory foam, gel, innerspring, hybrid |
| Firmness | Medium feel | Varies by brand; shop by firmness on site |
| Trial | 100 nights | Varies by brand; check the product page |
| Warranty | 20 years | 10-year warranty included on select online mattresses |
| Shipping | Free shipping | Delivery and set up included on select online mattresses |
| Returns | Free returns | Haul away included on select online mattresses; confirm return terms per item |
| Extras | None listed beyond trial and warranty | Up to 4% rewards on qualifying purchases; terms apply |
Construction and materials
The Amerisleep AS3 is a medium-feel all-foam mattress. Amerisleep builds it with Bio-Pur, a plant-based foam, and describes it as balancing support and softness for every sleep position. That is one construction, one feel, and one set of terms you can read before you order.
Costco is not a single mattress. It is a retailer with a mattress category that includes memory foam, gel, innerspring, and hybrid compositions, plus a range of brands and firmness levels. You shop by firmness, by composition, and by brand, which is useful if you do not yet know what you want.
The practical difference: with the AS3 you are evaluating one build. With Costco you are evaluating a shelf. Neither is wrong, but they ask different things of you. The AS3 asks whether that one medium-feel foam bed suits you. Costco asks you to narrow a large selection down to one product, and then to read that product's own terms.
Feel and firmness
The AS3 has a medium feel, which sits in the middle of the firmness range and suits a broad mix of side, back, and combination sleepers. Amerisleep positions it to balance support and softness, so you get cushion at the shoulders and hips without a heavy sink.
At Costco, firmness is a filter, not a given. You can shop by firmness across soft, medium, and firm options, and by composition, so the feel depends entirely on which mattress you pick. If you already know you want a medium feel, the AS3 gives you that out of the box. If you want to try several feels before deciding, Costco's range is the advantage.
Pressure relief
Pressure relief is about how well a mattress cushions the heavier parts of your body, mainly the hips and shoulders, while still keeping your spine in a neutral line. The AS3's all-foam build with Bio-Pur is designed for exactly this: foam contours to contact points and spreads load across a wider area, which is why foam beds are a common choice for side sleepers.
At Costco, pressure relief depends on the mattress you choose. A memory foam model will contour similarly to the AS3. An innerspring model will push back more at the contact points. There is no single answer for the retailer, so check the composition and firmness of the specific mattress you are considering, and read its product page for how the brand describes its feel.
Cooling
The AS3 is an all-foam bed built with plant-based Bio-Pur foam rather than traditional memory foam. All-foam beds do not have the airflow of a coil layer, so hot sleepers should weigh construction first.
Costco's selection includes gel and innerspring options alongside memory foam. Gel foams are designed to move heat away from the surface, and innerspring builds have natural airflow through the coil layer. If you sleep hot, this is a case where browsing helps: you can compare a gel model against an innerspring model on the same site. Just confirm the specific model's materials before you buy, since cooling claims vary by brand.
Motion isolation
Motion isolation is how much movement transfers across the bed when one person shifts or gets up. All-foam mattresses are generally strong here because there are no coils to bounce energy along. The AS3, as an all-foam bed, is built in that category.
At Costco, motion isolation depends on the composition you pick. Memory foam and gel models isolate motion well. Innerspring and hybrid models transfer more movement because coils flex and respond. If you share a bed and motion transfer matters to you, lean toward a foam model in either case, and check the specific product's construction before ordering.
Trial period and warranty
The AS3 comes with a 100-night trial and a 20-year warranty, both from Amerisleep. Shipping and returns are free, so if the mattress does not work out, you are not paying to send it back. Those terms apply to the AS3 specifically, and they are the same no matter where you read about it.
Costco's mattress page lists a 10-year warranty included on select online mattresses, along with delivery and set up and haul away included on select online mattresses. Trial length is not stated at the retailer level, so it varies by the brand you buy. Before you order, open the specific product page and confirm three things: the trial length, the warranty length and what it covers, and the return process if you change your mind. Those terms belong to the mattress brand, not to Costco as a whole, and they can differ from one product to the next.
Price and value
We do not list prices on this page, because mattress pricing changes with sales, sizes, and promotions, and the number you see today may not be the number you see tomorrow. What matters more than the sticker is what you get for it.
With the AS3, you are paying for one specific build: medium-feel all-foam, plant-based Bio-Pur, a 100-night trial, a 20-year warranty, and free shipping and returns. That is a complete package with terms you can read in one place.
At Costco, value depends on the mattress you pick. The retailer lists delivery and set up, haul away, and a 10-year warranty included on select online mattresses, plus up to 4% rewards on qualifying purchases with terms that apply. Those extras are real, but they attach to qualifying items, so check the product page to see which ones apply to the mattress you want.
Who should buy each mattress
Buy the Amerisleep AS3 if: you already know you want a medium-feel all-foam mattress, you want the trial and warranty terms in writing from one maker, and you want free shipping and returns without hunting for them. It suits side, back, and combination sleepers who want foam contouring without a heavy sink, and it is a straightforward buy if you would rather evaluate one bed than a shelf of them.
Buy from Costco if: you want to compare multiple brands, compositions, and firmness levels in one place before committing, or you are drawn to the included extras on qualifying online mattresses, such as delivery and set up, haul away, and the 10-year warranty. It also makes sense if you are not yet sure whether you want foam, gel, innerspring, or hybrid, and you want to narrow that down with filters rather than guess. Just check the specific product page for that mattress's trial, warranty, and return process before you buy.
The Amerisleep AS3 is the pick for a buyer who wants one clearly specified medium-feel all-foam mattress with a 100-night trial, a 20-year warranty, and free shipping and returns. Costco is the better starting point if you want to browse many brands and compositions and you are willing to read each product's own terms before deciding. If you are still weighing a third option, the Saatva Classic offers a 365-night trial, a lifetime warranty, and free white-glove delivery with old-mattress removal, which is the longest trial and warranty on this page.
Frequently asked questions
Should I buy Costco or Amerisleep?
Buy the Amerisleep AS3 if you want a single medium-feel all-foam mattress with a 100-night trial, a 20-year warranty, and free shipping and returns, all from one maker. Buy from Costco if you want to compare many brands and compositions in one place and you are willing to check each product page for its own trial, warranty, and return terms. The right answer depends on whether you know what you want or still need to narrow it down.
Does Costco have a mattress trial?
Costco's mattress page does not state a single trial length for the category. Trial terms belong to the mattress brand you buy, so they vary from one product to the next. Before ordering, open the specific product page and confirm the trial length, what happens if you return it, and who pays for the return.
What warranty does Costco include on mattresses?
Costco lists a 10-year warranty included on select online mattresses. That applies to qualifying items, not necessarily every mattress in the category. Check the product page for the specific mattress you want to see whether the 10-year warranty applies and what it covers.
Is the Amerisleep AS3 good for side sleepers?
The AS3 has a medium feel and an all-foam build with plant-based Bio-Pur, which is designed to balance support and softness across sleep positions. That combination typically suits side sleepers, because foam cushions the hips and shoulders while keeping the spine in a neutral line. If you sleep on your side and want a foam bed, the AS3 is a reasonable place to start.
Can I return a mattress bought at Costco?
Costco lists haul away included on select online mattresses, which covers removal of the old mattress on delivery. Return terms for the mattress itself depend on the brand and the specific product, so confirm the return process on the product page before you buy. With the AS3, Amerisleep lists free returns as part of its 100-night trial.