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Contract Budget Base

Contract Budget Base (CBB)

EVM Terms Reviewed by forProject Technology - updated Sep 2026
Quick definition: The Contract Budget Base (CBB) is the Negotiated Contract Cost plus the estimated cost of any Authorized Unpriced Work — the total budget authorized under the contract.

The CBB can be read from either direction. From the contract side it is the Negotiated Contract Cost plus the estimated cost of Authorized Unpriced Work. From the budget side, the Total Allocated Budget is the Performance Measurement Baseline plus Management Reserve, where the PMB is Distributed Budget — the Control Account and Summary Level Planning Package budgets — plus Undistributed Budget. The two should reconcile: absent an Over Target Baseline, the Total Allocated Budget equals the Contract Budget Base. Where the Total Allocated Budget exceeds it, that gap is the OTB.

Why it matters

CBB is the top-level number that everything else on the budget side reconciles to. If the sum of all the lower-level budgets and reserves doesn't match the CBB, that's a signal something in the budget log is out of balance. It's a key figure checked during formal reviews like an Integrated Baseline Review.

Also known as
N/A
Used in
CBB = Negotiated Contract Cost + estimated cost of Authorized Unpriced Work; reconciliation against Total Allocated Budget

FAQ

Is CBB the same as Budget at Completion?
No — CBB includes Management Reserve, while BAC is the performance budget for the defined work scope and doesn't include the reserve held back by management.
Why are there two ways to calculate CBB?
They're meant to be two paths to the same total. One builds up from the negotiated contract price and changes; the other builds up from all the individual budgets and reserves. Comparing them is a useful check that the numbers reconcile.
Definition maintained by forProject Technology.
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