Guides

How to Price Change Orders on T&M: Labor Rates, Burden, and Markup

Updated Jul 13, 2026

Change orders are where labor rates stop being an internal worksheet and start being contract language. Even on a lump-sum job, changed and added work is priced from an agreed rate sheet the moment scope can't be pre-measured — and industry analyses put that slice at 10–15% of total contract value on major projects. Price it well and change orders carry the margin the bid gave away. Price it thin and every directed hour digs the hole deeper, with your own signature on the rate.

This guide covers the labor side of T&M change-order pricing: the three ways changed work gets priced and where the risk sits in each, why the burdened labor rate — not the markup — decides the money, what the OH&P cap does and doesn't cover, force-account work, and the two protections that survive an audit: a defensible rate and a snapshot of the rates that priced the work.

In this guide:

• The three ways changed work gets priced
• The rate sheet is the contract
• The markup cap — OH&P conventions and limits
• In the rate vs. in the markup
• Force account: T&M with the markups written for you
• Rates step mid-job — price both sides, and snapshot
• Paper that survives the audit
• From rate to change order

The three ways changed work gets priced

Most contracts give the parties three paths for pricing a change, and the general conditions usually list them in this order:

T&M is the path of last resort in the contract language and the path of first resort in real life: unknown conditions, acceleration, out-of-sequence work, and owner-directed extras all land there because nobody can honestly fix a price for them in advance. And notice what the T&M row does to your exposure. The owner takes the quantity risk — that's the point of T&M — but in exchange the markup gets capped and the rates get scrutinized. Everything you will ever make on that change order is already inside two numbers you agree to up front: the labor rate and the markup. The rest of this guide is about getting those two numbers right.

The rate sheet is the contract

On T&M changed work, the labor rate isn't an internal estimate — it's the exhibit. The T&M rate sheet attached to the contract or the change order itself says what one hour of each classification bills, per tier, and once it's signed you don't get to remember a burden you forgot.

That rate has to be a real labor rate build-up: the wage, the wage-attached additions, the benefit contributions, the payroll burdens, insurance, and consumables, finalized with your margin or markup convention. On the carpenters line this guide series uses throughout, a $46.28 wage carries a true fully burdened cost of $75.43/hour — 63% over the wage before a dollar of profit. For a union shop, the wage-and-fringe inputs come straight off the Schedule A, employer lines only. None of that math changes because the work is a change order. What changes is what happens when the math is wrong: on a bid you quietly make less than you thought; on a change order the thin rate is printed, signed, and applied to every directed hour until the job ends.

The markup cap — OH&P conventions and limits

Nearly every contract limits what you can add on top of cost on changed work — the overhead-and-profit ("OH&P") clause, usually in the supplementary or general conditions rather than anywhere near the word "rates." The shapes vary, but the common conventions look like:

• A single percentage on self-performed cost — often somewhere in the 10–20% range, covering overhead and profit together.
• Tiered percentages — one markup on your own labor, a smaller one on subcontracted work, sometimes a combined cap so markups can't stack through the sub chain.
• Separate overhead and profit lines, each a stated percentage on a stated base.

There is no industry-standard number — the percentage is negotiated contract language, and on public work it's often printed in the agency's specifications. What is standard is the trap: the cap fixes the convention, and markup and margin are not the same math. On the $75.43 cost, a 15% markup bills $86.75; a 15% margin bills $88.74. If the contract says "15% markup on cost," price with markup math — quote the margin number and the difference is a concession you'll make in the first audit, two dollars an hour at a time.

Here is the whole change-order money picture in one hour of work, priced under a 15% cap:

The below-the-line row is deliberately extreme — nobody sets out to bill bare wages — but the mechanism is exactly how the real, milder version works. The markup percentage is fixed; it cannot stretch to cover a cost your rate left out. Forget one fringe line, use last year's benefit rates, or leave the consumables out of the build-up, and a couple of dollars an hour falls through the same gap. On a 2,000-hour change order — a crew of five for ten weeks — every dollar an hour you failed to put in the rate is $2,000 the cap will not give back, and the same thin rate prices the next change order too.

In the rate vs. in the markup

Which brings us to the question that decides most change-order rate disputes: for every cost you carry, does it live inside the labor rate, or is it part of what the markup covers?

Neither bucket is wrong; contracts and estimating books draw the line in different places. The rule is that every cost must land in exactly one — and the contract's own definitions decide which. The expensive failures are the costs that quietly land in neither: field supervision that isn't a billable classification on the rate sheet, per diem and travel nobody listed, small tools and safety consumables left out of the build-up on the theory that "the markup covers it" — against a markup clause that says it covers overhead and profit, full stop. Read the OH&P definition once, then walk your build-up line by line and ask where each dollar bills. Anything with no answer is coming out of your 15%.

The same discipline protects you in the other direction. If small tools are already a per-hour line inside your rate, they can't also appear as a separate line item on the change-order invoice — a double-dip an auditor will find, and the credibility cost spreads to lines you priced honestly.

Force account: T&M with the markups written for you

On public work the T&M path has a formal name — force account — and a defining feature: the owner writes the build-up for you. Agency specifications prescribe what changed-work labor pays, typically the wages and fringes you actually pay, statutory burdens, equipment at published rental rates, and fixed percentages for overhead and profit on each cost category. Several state DOTs publish the entire structure — the fringe treatment, the markup on labor versus equipment versus materials — and audit force-account bills against it line by line.

That changes where your leverage lives. On private T&M work you negotiate the rate; on force account the percentages are non-negotiable, so the only variable left is how completely you can document actual cost. The wage block and every fringe line need a source the auditor recognizes — for a union shop, that's the Schedule A itself, employer contributions sorted from employee deductions, because force-account auditors know those agreements and will strike a deduction billed as a cost. A contractor who can produce the agreement, the build-up, and the daily hours wins force-account arguments; a contractor with a blended "shop rate" and no backup donates the difference.

Rates step mid-job — price both sides, and snapshot

A change order is priced on one date and worked across many. Union agreements step on fixed dates — June 1 is common, and the schedule usually prints the next step right on the page — while open-shop costs step whenever your benefits renew or your insurance mod changes. Every one of those steps lands in the middle of some change order. Three protections:

1. Put effective dates on the rate sheet. A rate sheet with no dates is an invitation to apply today's rate to next year's hours — in whichever direction hurts you. State the window each rate covers and the escalation that applies past it.
2. Price both sides of a known step. If the work will span June 1 and the new wage is already printed, price the hours on each side of the step explicitly. It's more defensible than a blended rate and it removes the argument entirely.
3. Snapshot the rates that priced the work. When the agreement steps or a benefit renews, the rate library you price tomorrow's work from has to move — but the rates inside signed change orders must not move with it. Keep a frozen copy of the build-up behind every signed number, so you can prove which step priced the work and show the delta when you ask for escalation. (This is how CrewMix behaves by design: estimates snapshot their rates, so a mid-job step never silently reprices signed work.)

Paper that survives the audit

Change-order labor gets audited more than any other billing, because it's the money the owner never planned to spend. The rate does half the work; the paper does the rest:

• Daily T&M tickets, signed daily. Names, hours, classifications, and what the crew did — signed by the owner's representative while memories are hours old, not at month-end.
• Classifications that match the rate sheet. Every name on a ticket bills as a classification that exists on the signed sheet. A "working foreman" on the tickets who isn't on the rate sheet is an argument you scheduled for later.
• Tiers split the way the schedule actually splits them. Overtime hours billed at the OT rate the build-up produced — which is not the ST rate × 1.5 — under the same daily/weekly triggers the labor agreement uses. An auditor who finds multiplier math in the OT column reprices the whole column.
• The backup behind the rate. Keep the full build-up — wage source, each fringe line, each burden percentage and its base — ready to produce. The rate-sheet guide covers the negotiation-and-audit mechanics in detail.

From rate to change order

Change-order pricing is the rest of this guide series pointed at a signature: the Schedule A (or your own benefits ledger) supplies the wage-and-fringe inputs, the build-up turns them into a defensible cost, the burden math keeps the tiers honest, and the rate sheet carries the result into the contract — where the markup cap makes every line of it matter.

CrewMix runs that chain end to end: the AI agreement import reads wages and fringes straight off the Schedule A PDF, the build-up editor prices every classification's ST, OT, and DT from its own wage, estimates price the whole crew schedule and export the backup — and every estimate snapshots its rates, so the number you signed is the number you can prove, no matter what steps mid-job.

However you build it: one bucket for every cost, dates on every rate, tickets signed daily — and never let a capped markup stand in for a burden you could have put in the rate.