What Should a GC Do When a Sub Falls Behind?

By Wyatt Cooper · Published October 22, 2026 · 7 min read

Key takeaways

Measure the slip against the schedule and the look-ahead before you raise it, so the conversation is about days and crews, not feelings.
Talk first, then put it in writing: a notice that names the work, the days behind, what you need and the cure period your subcontract gives.
Supplementing the sub's crew and charging the cost back is the usual middle step; it only holds up if the subcontract allows it and the notice came first.
Termination for default is the last step, and the one most often fought; follow the subcontract's procedure to the letter.

When a subcontractor falls behind, measure the slip against the schedule first, then meet the sub's project manager and ask for crew numbers and a date. If it doesn't improve, send written notice under the subcontract: the work, the days behind, the crew or recovery plan you need and the cure period. If the sub still doesn't cure, supplement its forces and back-charge the cost as the subcontract allows. Terminate for default only as a last step, following the subcontract exactly.

Measure it before you raise it

A sub that feels slow and a sub that is behind are different conversations. Put numbers on it: the activities in the latest schedule update or three-week look-ahead, their planned and forecast finishes, the working days lost, and whether the work is on the critical path. Then pull the manpower from your daily logs: a crew of four on work planned for eight explains most slips without anyone having to argue.

Check your own side too. Is the sub waiting on an RFI answer, a late submittal review, another trade's area or your hoist? A notice for a delay the GC caused is the fastest way to lose the next argument. (More from the GC's seat: the general contractor's guide and the project lifecycle.)

The escalation ladder

From a conversation to termination: each step, what it needs and what to keep
Step	When	What you send or do	What to keep
1. Talk	The first missed look-ahead week	Meet the sub's PM and foreman; ask for crew size and a recovery date	Meeting notes, the look-ahead, manpower from the daily logs
2. Written notice	Still behind after the agreed date	Notice under the subcontract's default or schedule article: work, days behind, what's required, cure period	The notice, proof of delivery, a copy to the sub's surety if the subcontract or bond calls for it
3. Recovery plan	With the notice	Ask for the sub's plan: added crews, hours, a date for each area	The plan, and the daily logs that show whether the crews arrived
4. Supplement	The cure period ends without a cure	Second notice; add labor (yours or another sub's) to the work, as the subcontract allows	Hours, rates, materials and equipment by day, for the back-charge
5. Terminate for default	The sub still can't or won't perform	Notice of termination exactly as the subcontract requires; notify the surety	The full record from step 1, and photos of the work in place

What a notice to the sub says

Keep it short, factual and tied to the contract. Name the subcontract article you rely on, the work that is late in schedule terms, what you need by when, and what you will do if it doesn't happen. Leave out adjectives. A fictional example:

Notice of failure to maintain schedule: Crestline Interiors, Larchmont Commons

To: Crestline Interiors, attention project manager. Copy: Crestline's performance bond surety, as subcontract article 12 requires.
Date: March 30. Sent by email and certified mail, as article 21 requires.
Contract basis: Subcontract article 9 (schedule) and article 12 (default and supplementation).
The facts: Interior framing, floors 1 and 2, planned complete March 27 in the approved look-ahead. As of today 55% of floor 1 is framed and floor 2 has not started. Your crew averaged 4 framers from March 2 to March 27 against the 8 in your schedule submittal (daily logs attached).
What is required: Within 3 working days of this notice: 8 framers on site, and a written recovery plan finishing floor 2 framing by April 17.
If not cured: We will supplement your forces under article 12 and charge the cost to your subcontract, and may take further action under that article.

A notice to a subcontractor on a fictional job. Every name, date and article number is made up; use your subcontract's own.

1SuperintendentSees the look-ahead slip and the crew size in the daily logs
2Project managerMeets the sub and agrees a crew and a date
3Project managerSends written notice when the date passes, with the cure period
4SubcontractorCures with crews and a recovery plan, or doesn't
5Project managerCloses the notice, supplements or, as a last step, terminates

One sub falling behind, from the first sign to a decision

What public contracts show

Federal prime contracts set the pattern many subcontracts copy, flowing the owner's rights down to the subs. FAR 52.236-15(c) treats a failure to follow the Contracting Officer's schedule requirements as grounds for a finding that the contractor "is not prosecuting the work with sufficient diligence to ensure completion within the time specified". The default clause, FAR 52.249-10(a), lets the Government, "by written notice", terminate the right to proceed if the contractor "refuses or fails to prosecute the work or any separable part, with the diligence that will insure its completion within the time specified", and makes the contractor and its sureties liable for the resulting damage.

Two lessons carry over. The notice is written, and it is about diligence measured against the schedule. And the same clause, in paragraph (b), excuses delays beyond the contractor's control, such as unusually severe weather, if the contractor notifies in writing within 10 days, so ask what is stopping the sub before you assume it's crews. On federal jobs the Corps' schedule specification also expects a written recovery plan when progress falls behind (§3.9); a sub's plan becomes part of yours. When you do supplement, cost it as a back-charge, and the whole job's catch-up goes in a recovery schedule.

The bottom line

When a sub falls behind, numbers first, a conversation second, then a written notice that names the work, the days and the cure. Supplement and back-charge only after the notice, and keep termination for last.

Most disputes about a late sub are won or lost on the record: the look-ahead, the daily manpower and the notices. Keep it as you go.

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Sources

FAR 52.236-15, Schedules for Construction Contracts — Acquisition.gov (General Services Administration). Read October 22, 2026.
FAR 52.249-10, Default (Fixed-Price Construction) — Acquisition.gov (General Services Administration). Read October 22, 2026.
UFGS 01 32 01.00 10, Project Schedule (August 2026), §3.9 Failure to Achieve Progress — U.S. Army Corps of Engineers (Whole Building Design Guide). Read October 22, 2026.

Questions

How do you tell a subcontractor they are behind schedule?

Start with a meeting and numbers: the activities, the planned and forecast dates, and the crew size from your daily logs. If the agreed fix doesn't happen, follow with a written notice under the subcontract that states what is required and by when.

What is a cure period?

The time a subcontract gives the sub, after written notice, to fix a default before the GC can supplement its work or terminate. Its length and how notice must be sent are set by the subcontract, so read yours.

Can a GC add workers to a subcontractor's scope?

Usually, if the subcontract has a supplementation clause and the GC gave the required notice and the cure period ran out. The GC then charges the cost of the added labor back to the sub.

When can a GC terminate a subcontractor for default?

When the sub fails to cure after the notice the subcontract requires. It is the most contested step: follow the subcontract's procedure exactly, notify the surety if there is a bond, and take legal advice first.

What if the sub is late because of the GC?

Then it isn't a default. Check for unanswered RFIs, late submittal reviews, blocked areas and other trades before you send notice, and fix your side first; the sub may be owed time.