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Flat Foundation

Engineered to support your Stearns and Foster® mattress with a perfectly solid, flat surface.

Profile
$465.00
Free Delivery — Arrives in 2-3 Weeks
  • Designed in the USA
    Crafted with care and to last



Fashion
+ Function

The perfect mattress isn't complete without the perfect foundation. Our flat foundations are designed to take the place of a traditional box spring and can be placed directly on your existing bed frame.

SF Lux Estate mattress on a foundation
SF Lux Estate mattress on a foundation

Fashion


+ Function

The perfect mattress isn't complete without the perfect foundation. Our flat foundations are designed to take the place of a traditional box spring and can be placed directly on your existing bed frame.

SF Mattress on a foundation

CRAFTED TO

Complement



Constructed with the finest textiles, our Stearns & Foster® foundation is designed to enhance the look and feel of your mattress.


Why You'll Love It

SF Lux Hybrid mattress on a foundation



Perfect Match

Our solid surface foundation is crafted to provide years of stationary support. Designed and upholstered to complement our mattresses and your bedroom décor.

Why You'll Love It

SF Lux Hybrid Mattress on a foundation Mobile


Perfect Match

Our solid surface foundation is crafted to provide years of stationary support. Designed and upholstered to complement our mattresses and your bedroom décor.

An image showing the difference in height between the 5 and 9 inch foundations


Custom Comfort

Our foundations are available in a 9” height that matches a traditional box spring and a lower 5” profile for a more modern look that will easily fit through more narrow stairways.



Custom Comfort

Our foundations are available in a 9” height that matches a traditional box spring and a lower 5” profile for a more modern look that will easily fit through more narrow stairways.

SF_flatbase2.original
SF mattress on a foundation

Crafted


For you

Constructed with the finest textiles that enhance the look and feel of your mattress, our Stearns & Foster® Foundation is designed to complement your style.

Looking to Upgrade Your Bed?

Get a $200 instant gift when you purchase an Ease Base with your mattress. The Ease Base adds unlimited adjustable positions to help you sleep soundly at night and enhance your sleep sanctuary.

$200 Instant Gift with an Ease Base

Benefits:

  • Unlimited Head and Foot Positions
  • Wireless Remote Control
  • Zero Gravity Preset Position
  • Free Delivery and In-Home Set-Up

Shop Now

Looking to Upgrade Your Bed?

Get a $200 instant gift when you purchase an Ease Base with your mattress. The Ease Base adds unlimited adjustable positions to help you sleep soundly at night and enhance your sleep sanctuary.

$200 Instant Gift with an Ease Base

Benefits:

  • Unlimited Head and Foot Positions
  • Wireless Remote Control
  • Zero Gravity Preset Position
  • Free Delivery and In-Home Set-Up

Shop Now

Product Specifications

Size Availability

Twin: 74L" x 38W"

Twin Long: 79L" x 38W"

Full: 74L" x 53W"

Queen: 79L" x 60W"

Split Queen: 79L" x 30W" (each piece/ 2-piece foundation)

King/Split: 79L" x 38W" (each piece/ 2-piece foundation)

CA King/Split: 83L" x 36W" (each piece/ 2-piece foundation)

Product Weight

High Profile 9"

Twin: 31 lbs.
Twin Long: 35 lbs.
Full: 42 lbs.
Queen: 48 lbs.
Split Queen: 60 lbs. (30 lbs each piece)
King/Split: 70 lbs. (35 lbs each piece)
CA King/Split: 70 lbs. (35 lbs each piece)

Low Profile 5"

Twin: 25 lbs.
Twin Long: 29 lbs.
Full: 38 lbs.
Queen: 46 lbs.
Split Queen: 58 lbs. (29 lbs each piece)
King/Split: 58 lbs. (29 lbs each piece)
CA King/Split: 56 lbs. (28 lbs each piece)

Warranty & Returns

Warranty

Your Stearns & Foster foundation is covered under a 10-Year Limited Warranty.

View warranty details.

Return Policy

This product cannot be returned and the 90-Night Trial does not apply.

Care Instructions:

We made caring for your foundation straightforward and easy.

Read our product care instructions.

Rated 4.784 out of 5 stars

Read Our Reviews

Rated 4.784 out of 5 stars
125+ REVIEWS
AVERAGE OF 4.8 STARS

Filter Reviews

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Rating
(113)
(5)
(2)
(2)
(3)
Rated 5 out of 5 stars
5
Flat Foundation
Apr 1, 2026
Source:
Stearns & Foster
Sweepstakes

Attention: Anyone with a backache!

Apr 1, 2026
Robin, South Lyon, MI
We were looking for the firm mattress we purchased for another home two years ago when my back started aching. All research shows if your spine is old and not in the best shape, the firmer the better. Alas, the mattress was not available in any store anymore, so we called Sterns and Foster directly and were told "sure, we can make that mattress again for you". We were thrilled and within just 2 days my back was feeling much better. This was such a blessing, as I just started drug therapy for my cancer and felt the care, concern and urgency to get this to us quickly was genuine and heartfelt. I hope the "paying forward" that was done by your salesperson and company comes back to you tenfold. Thank you!!!!
Rated 5 out of 5 stars
5
Flat Foundation
Mar 28, 2026
Source:
Stearns & Foster
Sweepstakes

Mattress and Boxspring

Mar 28, 2026
Farmher , Washington PA
Great quality. Top notch construction.
Rated 5 out of 5 stars
5
Flat Foundation
Mar 8, 2026
Source:
Stearns & Foster
Sweepstakes

Makes a difference when you sleep on Stearns and Foster.

Mar 8, 2026
ScottE, Jacksonville,FL
We already had a Stearns and Foster Estate Lux mattress....not for sure the reason the store that sold it to us didn't sell us the 9" Flat Foundation as well. Anyway that was quickly replaced with something much better. The Stearns and Foster 9" foundation is a must have if your going to buy there mattress. Our rest has been so much better no noise, great support and a good nights sleep. So happy we went with this company. Finally we wake up feeling refreshed and ready to take on the day.
Rated 5 out of 5 stars
5
Flat Foundation
Feb 22, 2026
Source:
Stearns & Foster
Sweepstakes

Perfect for a 15 inch Mattress

Feb 22, 2026
William S, Granite City IL
Great quality and the perfect choice to use with a 15 inch mattress when using a bed frame. Provides great support for that comfortable STEARNS and FOSTER MATTRESS
Rated 5 out of 5 stars
5
Flat Foundation
Feb 13, 2026
Source:
Stearns & Foster
Sweepstakes

Great quality

Feb 13, 2026
Better back, Ft Worth, TX
The foundation supports the mattress fully and with no flexibility. Solid support and fits correctly.
Rated 5 out of 5 stars
5
Flat Foundation
Feb 12, 2026
Source:
Stearns & Foster
Sweepstakes

Very Well Made

Feb 12, 2026
J Cunningham, Canton, Ga
Not only is the product very high-quality, but they truly do have white glove delivery. Excellent company in A+ service.


BUILD THE BED OF YOUR DREAMS

SF Reserve mattress on a flat foundation in a styled room

Discover the handmade details and finest materials that make our mattresses truly exceptional.

Shop Mattresses

Lux Estate Mattress in a styled room raised on a base

Upgrade to custom comfort with our Ease® Power Base—for a seamless sleep experience.

Shop Power Bases

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