Serta iSeries 4000 Plush Mattress Review

Updated May, 2021
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While Serta iSeries 4000 Plush is a fantastic mattress at this price point, our #1 pick for 2021 is SAATVA mattress. Saatva is a luxury mattress shipped to your door (unlike other bed in a box brands dropped off on your doorstep) w/ FREE white-glove delivery & setup. They have over 50,000 5-star reviews, and they're incredibly comfortable (for all sleep positions).

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Bottom Line

Manufactured by one of the most reputable bed brands in the US, the Serta iSeries 4000 Plush is a quality hybrid mattress. It features 1025 individually wrapped coils, multiple layers of memory foam, and four different cooling features to control your temperature while you sleep. The iSeries 4000 Plush is a great choice for side sleepers, couples, and those who toss and turn.

Get the Serta iSeries 4000 Plush if...

  • You want the best of foam and coils. Are you having a tough time deciding between pressure relieving memory foams and ultra-supportive coils? With the iSeries 4000 Plush, you don't have to! This mattress includes memory foams and coils, so you can reap the benefits of both.
  • You sleep hot. If you depend on temperature control to sleep comfortably, the iSeries 4000 Plush is a great option. This bed features carbon infused memory foam, a temperature regulating cover, and gel infused memory foam to keep you cool while you sleep.
  • You're a side sleeper. The Serta iSeries 4000 has a plush firmness level, perfect for side sleepers who need cradling comfort and adaptive lumbar support simultaneously.

Skip the Serta iSeries 4000 Plush if...

  • You sleep on your back. If you sleep exclusively on your back, this mattress's plush firmness level may not be firm enough to provide you with the kind of lumbar support you need to sleep comfortably.


  • Advanced cooling technology
  • Individually wrapped coil system
  • Ideal for side sleepers
  • 10-year warranty
  • Genuine US product


  • No sleep trial included
  • Can't buy directly from Serta's website


The Serta iSeries Hybrid 4000 has a plush firmness level, optimal for side and combination sleepers looking for shoulder and hip pressure relief. If you like superior cushioning and feeling more "in" your mattress than "on" it, the iSeries Hybrid 4000 caters to this preference.

Construction & Design

  • Max Cold Cover: This mattress cover is made from temperature regulating, high performance fibers that create a cool-to-the-touch sensation.
  • UltraCold System: This layer of extra-cool carbon memory foam channels excess heat away to keep the mattress comfortably cool.
  • Carbon Fiber Memory Foam: This high quality foam layer draws excess heat away from your body while providing optimal lumbar support.
  • EverCool Fuze Gel Foam: This cooling gel-infused foam layer further provides temperature control by increasing airflow and dissipating heat.
  • 1025 Hybrid Support System with Best Edge Foam: This advanced coil system uses individually wrapped coils that provide targeted support and adapt to your body's movements throughout the night. Best Edge foam encasement reduces roll-off and increases usable surface area.

Support & Motion Isolation

This mattress's 1025 individually wrapped coils combined with quality layers of body conforming memory foam make the Serta iSeries 4000 Plush great at providing motion isolation. The coil system provides targeted support and reduces motion transfer across the bed, while memory foam layers absorb impact from sudden movements, allowing you to sleep undisturbed. it's a great choice for couples!

Like this bed's motion isolation performance, the Serta iSeries 4000 Plush performs exceptionally at edge support. The border of this mattress is encased in an extra deep high density foam rail which reinforces its edges. This means that more surface area can be used, and potential roll-off and sagging are greatly reduced.

Reasons to Buy the Serta iSeries 4000 Plush

  1. You toss and turn in your sleep. If you're a restless sleeper, the Serta iSeries 4000 Plush is a great option. This mattress relieves pain instead of causing it, allowing you to relax into its memory foam layers and sleep soundly.
  2. You share your bed with someone. The Serta iSeries 4000 Plush is excellent at reducing motion transfer across the bed thanks to its 1025 count individually wrapped coil system. The coils respond to your body independently, so you won't feel any motion across the bed, allowing both of you to sleep soundly.
  3. You like supporting US-based companies. If you love buying from US brands, this is a purchase you can feel good about. The Serta iSeries 4000 is designed and manufactured in the US, so your purchase supports the domestic manufacturing industry and economy.

Reasons to Avoid the Serta iSeries 4000 Plush

  1. You want an eco-friendly option. This Serta mattress is CertiPUR-US certified, meaning it's made with safe, high-quality materials. This certification doesn't mean it's eco-friendly though! Look for a natural latex product with a GreenGuard certification if you want to make an environmentally conscious purchase.

The Serta iSeries 4000 Plush is an ideal choice if you want a great hybrid for side sleepers at an affordable price. You can get the Serta iSeries 4000 Plush for a great price, today!

Check out our Top 10 Mattress Picks of 2021, here!

Where can I find a great, affordable mattress (in 2021)?

If you're searching for a healthy, affordable mattress that's comfortable, relieves pressure, and has friendly policies; check out these 5 (in 2021):

  1. Saatva Mattress - fantastic for all sleep positions, and is rated our Best Mattress of 2021.
  2. Amerisleep - great for responsive pressure relief.
  3. Puffy - feels like you're sleeping on a cool cloud (at a good price).
  4. Ghostbed - beautiful, plush cover w/ aerated latex and healthy spinal alignment.
  5. Winkbeds - 3-stage back relief with free shipping and returns.

Read our short, well-researched 10 Best Mattresses of 2021, here. Our ultimate goal is to help you pick your perfect mattress online, today!

Check Price →
Get $200 off, purchases over $1000!

Saatva is our top pick for the #1 mattress in 2020! They're a luxury mattress shipped with FREE white-glove delivery & setup (different than regular bed in a box brands put on your doorstep). They have over 50,000 reviews.

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Get $200 off your order of $1,000 or more, today!