AWS bill line item
HeavyUsage:m5.large
The recurring charge for a Reserved Instance you've already committed to. It's billed whether or not a matching instance is running that hour.
Reserved Instance recurring fee
Verified against official AWS documentation last checked
Why it shows up
Confusing because it keeps appearing even after you stop using the matching instance type: an RI is a billing commitment, not a resource, so this line keeps charging for the full term regardless of whether matching usage occurs that hour.
"Heavy" is a holdover from AWS's early Light/Medium/Heavy Utilization RI options; the label stuck as the internal billing string even though AWS replaced that customer-facing naming with upfront-payment options years ago.
How to cut it
- Only reserve capacity for steady-state workloads, not anything that might get right-sized or decommissioned mid-term.
- Prefer regional (not zonal) scope and size-flexible instance families so the reservation can apply across more of the running fleet.
- Watch for reservations no longer matching any usage, then modify or sell them rather than letting them run out unused.
How to read this code
:instanceType suffixThe specific instance type or size a charge applies to, e.g. BoxUsage:m5.large. One line per distinct type in use.
Source
Source: AWS docs →Found HeavyUsage:m5.large on your own bill?
Drop your Cost Explorer CSV into the AWS Bill Analyzer. It'll flag line items like this one on your own bill and link straight back to the fix.
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