AWS Savings Plans vs Reserved Instances 2026: Which to Buy

AWS Savings Plans are commitment-based pricing models where you agree to a consistent amount of compute usage (measured in dollars per hour) for a 1-year or 3-year term. In return, AWS gives you a discount of up to 72% compared to On-Demand pricing.

There are three types: Compute Savings Plans (most flexible, apply across EC2, Fargate, and Lambda regardless of region, instance family, OS, or tenancy), EC2 Instance Savings Plans (scoped to a specific instance family and region, deeper discount), and SageMaker Savings Plans (for ML workloads).

The key advantage is flexibility. If you change instance types, move regions, or shift workloads between EC2 and Fargate, Compute Savings Plans automatically apply. You never have unused commitments sitting idle because they follow your usage.

Reserved Instances (RIs) are the original AWS commitment model, introduced in 2009. You reserve capacity for a specific instance type, in a specific region and Availability Zone, for a 1-year or 3-year term. Discounts reach up to 75% for Standard RIs.

There are two types: Standard Reserved Instances (deepest discount but least flexible — locked to instance type, platform, tenancy, and AZ) and Convertible Reserved Instances (slightly lower discount but you can exchange them for different instance types within the same family or across families).

RIs are ideal when you have high confidence in your instance type and region for the full term. They also provide capacity reservation in a specific AZ, which Savings Plans do not.

The fundamental difference is scope of commitment. Savings Plans commit you to a dollar-per-hour spend rate. Reserved Instances commit you to a specific instance configuration. This distinction drives every other trade-off.

Savings Plans automatically apply the best available discount across your usage, so you never have to manually match commitments to instances. RIs require you to align your commitment to actual running instances — any mismatch means you are paying for unused reservations.

For teams that change instance types frequently, run containers on Fargate, or use Lambda extensively, Savings Plans are almost always the better choice. For teams with rock-steady EC2 fleets that rarely change, Standard RIs offer slightly deeper discounts and guaranteed capacity.

Standard RIs give the deepest discount (up to 75%) but lock you into one instance type, platform, and AZ for the entire term. If your workload moves or your architecture evolves, you are stuck paying for unused capacity.

Convertible RIs sacrifice about 9% of that discount (up to 66%) but let you exchange the reservation for a different instance type, family, OS, or tenancy. This makes them a safer bet for teams planning migration or modernization during the commitment term.

In practice, many teams find that Convertible RIs and EC2 Instance Savings Plans occupy a similar niche. Both offer comparable discounts with regional scope. The difference is operational: Savings Plans auto-apply while Convertible RIs require manual exchange requests.

For most teams in 2026, Savings Plans should be the first commitment you make. The flexibility advantage compounds over time as your architecture evolves, and the discount gap versus RIs is small.

Savings Plans are especially strong if your team uses containers (ECS or EKS on Fargate), serverless (Lambda), or frequently changes instance types during right-sizing exercises. They are also better for organizations with multiple AWS accounts under an Organization, since they can apply across the payer account.

Reserved Instances remain the right choice in specific scenarios where their unique advantages matter. The 1-3% deeper discount compounds meaningfully at scale, and capacity reservation can be critical for launch-sensitive workloads.

Teams running large, stable EC2 fleets with high confidence in their instance type and region for the next 1-3 years will extract more value from Standard RIs than from equivalent Savings Plans.

The optimal commitment strategy layers both Savings Plans and Reserved Instances. Start with Savings Plans to cover your flexible baseline, then add RIs for predictable residual demand where deeper discounts justify the rigidity.

Here is the recommended sequence: First, analyze 60-90 days of usage data to establish your baseline compute spend. Second, purchase Compute Savings Plans to cover 60-70% of your stable baseline. Third, evaluate remaining uncovered usage and apply EC2 Instance Savings Plans or Standard RIs for steady-state workloads. Fourth, review monthly and adjust coverage as your fleet evolves.

The biggest mistake teams make is committing too aggressively too early. Buying 100% coverage on day one feels efficient but creates rigid commitments that penalize you when architecture changes.

Other common pitfalls include ignoring utilization monitoring (many teams have RIs sitting at 40-60% utilization), buying Standard RIs when Convertible would have been safer, and not considering the total cost of management overhead when comparing RI savings to Savings Plan simplicity.

Can I use both Savings Plans and Reserved Instances at the same time? Yes. AWS applies RIs first, then Savings Plans to remaining eligible usage. Layering both is the recommended approach for maximum savings.

Are Reserved Instances cheaper than Savings Plans? Standard RIs offer 1-3% deeper discounts for the same scope, but require more management and less flexibility. Convertible RIs and EC2 Instance Savings Plans offer roughly equivalent discounts.

What happens if I no longer need my Reserved Instance? Standard RIs can be listed on the RI Marketplace for resale. Convertible RIs cannot be sold but can be exchanged. Savings Plans cannot be transferred or cancelled.

Should I choose 1-year or 3-year terms? 3-year terms offer deeper discounts but lock you in longer. Start with 1-year terms until you have high confidence in your architecture stability.