[FIX] Comfort Systems USA: Q3 2026 Earnings Preview on Data Center Backlog Conversion

Comfort Systems USA (FIX), a large US mechanical and electrical contractor that installs HVAC, process piping and electrical systems in data centers, factories and hospitals, is scheduled to hold its earnings call on 2026-10-22[1], when it will report results for the third quarter of 2026, ending September 30, 2026. In the latest disclosed quarter, the second quarter of 2026, revenue rose 50.3% year over year to $3.27 billion, including 43.8% same-store growth[2]; net income was $441.6 million, or $12.53 per diluted share, operating cash flow was $1.14 billion, and backlog reached $14.06 billion on June 30[3]. On the July 24 call, management raised full-year 2026 same-store revenue growth guidance to the "mid to high 30%" range, cautioned that growth would moderate in the second half and especially in the fourth quarter against strong 2025 comparisons, and planned full-year capital expenditures of about 5% of revenue[4]. The Drillr earnings calendar, updated September 23, shows third-quarter consensus of $12.90 in EPS and $3.403 billion in revenue, against a third-quarter 2025 actual of $8.25 in EPS and $2.451 billion in revenue recorded in the same calendar, which implies roughly 39% expected revenue growth[5].

Three things matter most in this Comfort Systems earnings preview. The first is whether backlog keeps converting smoothly into revenue in a seasonally strong construction quarter: technology customers generated $1.917 billion, or 58.7% of second-quarter revenue[6], and backlog grew another 12.9% sequentially[7], so only third-quarter revenue read together with the September backlog can show whether growth is limited by skilled labor or whether new bookings are slowing. The second is margin quality: second-quarter gross margin was 25.9%[8], but 7.7% of that quarter's revenue came from upward estimate revisions on projects from earlier periods[9], nearly double the 3.9% for full-year 2025[10], so whether margin can hold 25.2% without that contribution rising further decides how much of the margin expansion can last. The third is whether cash flow keeps pace with net income: second-quarter free cash flow was $999 million[11], but contract liabilities rose from $2.120 billion to $3.231 billion in six months[12], and as those prepayments are worked down while modular plant purchases continue, third-quarter cash flow will show how much of it was customer money paid in advance.

Company Background and Business Structure

Comfort Systems USA is a holding company assembled from many local mechanical and electrical contractors: each operating company keeps its own brand and management, while headquarters handles capital allocation, risk control and shared practices and keeps buying regional mechanical and electrical contractors. The company had 51 operating locations as of June 30, 2026[2]. Since 2025 it has acquired contractors including Right Way, Century, Feyen Zylstra and Meisner[13], and on May 1, 2026, it bought Utah-based electrical contractor Hunt Electric for a preliminary price of $206.0 million[14], which management expects to add about $250 million in annualized revenue[15].

The company reports mechanical and electrical segments, and mechanical remains the larger business. In the second quarter, the mechanical segment generated $2.297 billion, about 70.3% of revenue, and the electrical segment generated $969.0 million, about 29.7%[16]. The mechanical business installs core HVAC equipment such as chillers, boilers, air handlers and cooling towers along with connecting piping and ducting, while the electrical business performs electrical construction and engineering in commercial and industrial markets[17]. By activity, new construction made up 75.1% of second-quarter revenue, existing building construction 14.8%, and service projects plus service calls, maintenance and monitoring about 10% combined[6].

Nearly all revenue comes from bid installation projects, and the customer mix has tilted sharply toward data centers. About 94.4% of revenue is earned on a project basis for installations in new facilities or system replacements in existing ones[17]; most contracts carry a fixed price, the company bills periodically as it hits milestones or incurs costs, and customers usually withhold a small portion as retainage[18]. Technology customers, mostly data centers, contributed $1.917 billion, or 58.7% of second-quarter revenue, up from 43.0% a year earlier; manufacturing contributed $535.4 million, healthcare $230.8 million, education $168.3 million, government $145.5 million and office buildings $92.5 million[6]. Management said on the call that modular operations, which prefabricate mechanical and electrical assemblies in factories, made up about 17% of first-half revenue and service about 10%, with service growing 7%[19], and the 10-K names modular construction as a capability the company plans to keep expanding[20].

Financial History and Current Position

Over the past three fiscal years, revenue and margins rose sharply together. Revenue grew from $5.207 billion in 2023 to $7.027 billion in 2024 and $9.102 billion in 2025, while operating income rose from $418 million and $749 million to $1.315 billion[21]; 2025 revenue grew 29.5%, with same-store activity contributing 26.1 percentage points[13]. Gross margin rose from 19.0% in 2023 to 21.0% in 2024 and 24.1% in 2025[22], and 2025 EPS was $28.88[23]. By segment, 2025 mechanical revenue was $6.67 billion, up 20.7%, and electrical revenue was $2.43 billion, up 61.9%[24].

Cash flow and backlog also set records in 2025, but much of the cash reflected the timing of customer payments. Operating cash flow was $1.19 billion in 2025, up from $849.1 million in 2024, and changes in billings in excess of costs and deferred revenue contributed $877.9 million of it[25]; capital expenditures were only $154.9 million[21]. Backlog ended 2025 at $11.94 billion, up 99.3% from $5.99 billion at the end of 2024[26].

Growth accelerated further in the first quarter of 2026, though margin included a sizable change-order gain. First-quarter revenue was $2.865 billion versus $1.831 billion a year earlier; gross margin was 26.3%, operating margin 17.0% and net income $370.4 million[27], with EPS of $10.51[5]. The 10-Q disclosed about $43.1 million of favorable developments, including change orders, on projects nearing completion[28], and an analyst on the call noted that gross margin was about 25.2% excluding that gain[29].

The second quarter of 2026 was the first time quarterly revenue exceeded $3 billion. Revenue rose 50.3% to $3.27 billion, gross profit was $844.2 million, and gross margin rose from 23.5% to 25.9%[8]; selling, general and administrative expenses were $287.0 million, falling from 9.7% to 8.8% of revenue[30], and operating income was $558.0 million, a 17.1% margin[16]. Net income was $441.6 million, or $12.53 per diluted share versus $6.53 a year earlier[3], and adjusted EBITDA was $600.5 million, or 18.4% of revenue[31].

As of June 30, 2026, the company held a large net cash position, but a meaningful share of it corresponds to work customers have paid for and the company has not yet performed. First-half operating cash flow was $1.528 billion, capital expenditures $288.8 million and free cash flow $1.242 billion[11], including a $103.0 million building purchase for the modular business in the first quarter[32]. At the end of June, cash was $1.855 billion, billed accounts receivable $3.279 billion and contract liabilities $3.231 billion[33]; total debt was just $54.1 million, the $1.10 billion senior credit facility was undrawn, and the company has posted positive free cash flow for 27 consecutive years[34]. In the first half it also repaid $100 million on its revolving credit facility[35] and raised the quarterly dividend from $0.80 to $0.90[15].

Operating Model

Revenue depends on how fast backlog is converted through construction. About 94% of revenue is project revenue and the rest is service; project revenue equals the portion of opening backlog recognized as work progresses plus short-cycle work booked within the quarter, and backlog equals prior backlog plus new bookings minus recognized revenue. Of the $14.06 billion backlog on June 30, the company expects about 65%–75% to be recognized over the next 12 months[36]; management said most traditional construction backlog is completed within 18 to 24 months, while modular backlog is stretching further out as customers lock up future capacity[37]. Of the 50.3% second-quarter revenue growth, same-store activity contributed 43.8 percentage points and acquisitions 6.5 points[2], and demand for HVAC and construction work is normally higher in the warmer second and third quarters[38].

Gross profit depends on executing fixed-price contracts, and estimate changes show up all at once in the quarter they are made. Gross profit equals revenue minus cost of services, which consists of labor, materials and equipment, subcontractors and overhead, and it includes cumulative catch-up adjustments from revised completion estimates on earlier projects, recognized in the quarter they become known[39]. In the second quarter, the mechanical segment earned $588.5 million of gross profit at a 25.6% margin and the electrical segment $255.7 million at 26.4%; after SG&A, which included $23.3 million of intangible amortization, mechanical operating income was $426.7 million, electrical $154.1 million and corporate expense $22.8 million, for a total of $558.0 million[16]. Labor productivity, material deliveries and change orders first change completion estimates and then move revenue and gross profit in the same direction within the same quarter, with almost no lag.

Operating cash flow is driven mainly by profit and the timing of customer payments, and prepayments can push cash flow above profit for a while. Operating cash flow roughly equals net income plus non-cash items such as depreciation and amortization, plus increases in contract liabilities (billings in excess of costs and deferred revenue), minus increases in receivables and contract assets, plus increases in payables. In the first half of 2026, net income was $812.0 million[31], the rise in contract liabilities added $1.062 billion, receivables absorbed $633.1 million, and payables and other current liabilities added $215.5 million, for operating cash flow of $1.528 billion[35]. When advance payments on large orders slow while construction continues, contract liabilities turn into revenue without bringing in new cash, and operating cash flow falls below profit with a lag of one to several quarters.

Capital spending has moved from an asset-light model to buying plants for modular capacity. Management plans to invest about 5% of revenue in owned modular facilities and said such investments typically pay back within one to two years[37]. The company has more than 3.5 million square feet of dedicated modular capacity, plans to exceed 4 million square feet by the end of 2026 and reach about 5 million by late summer 2027, and says all planned expansion is allocated to committed volume from existing customers[15]. Plant purchases reduce free cash flow first, and modular backlog turns into revenue only after the capacity comes online, several quarters later.

Industry and Competitive Position

The US mechanical and electrical contracting market is in a phase where demand far exceeds supply, and the binding constraint is skilled labor. The 10-Q describes an unprecedented demand environment in 2025 and the first half of 2026, along with rising labor costs and intermittent shortages and delivery delays for some materials and equipment[40]. The 10-K says skilled labor in the building and service trades has become increasingly scarce[41], management said on the first-quarter call that the biggest constraint on growth is "always and forever" labor, and first-quarter headcount was 3,000 to 4,000 higher than a year earlier[42].

The company's advantages rest on three things: its existing footprint in data center hubs, its modular capacity and its balance sheet. The 10-K and 10-Q repeatedly name operations in Texas, North Carolina, Indiana and Virginia as sources of incremental revenue[24][43], which are the regions where data center construction is concentrated. Management said new entrants in modular are arriving because customers want more capacity than the company can provide, not because competitors are trying to displace it[37]. At the end of June the company held $1.855 billion of cash against $54.1 million of total debt, with debt at 0.03 times trailing 12-month EBITDA[34], so it can fund acquisitions and plant purchases from its own resources.

The company's weaknesses and the limits of comparison are equally clear. Technology customers are close to 60% of revenue, and incremental growth is concentrated in a few operating locations[43], while fixed-price contracts mean that cost overruns not recovered through change orders cut directly into profit[18]. The company does not disclose bookings or single-customer revenue, and the available record contains no financial data for peer contractors, so its competitive position can be judged only from its own disclosures, without a quantitative peer comparison.

Core Debates

The three debates the third-quarter report can test map onto revenue, gross profit and cash flow: whether backlog converts at its recent pace, how much gross margin depends on estimate revisions, and whether cash flow keeps covering profit as prepayments are worked down. Each debate below sets out the evidence, the baseline and the falsifying conditions, without judging which outcome will occur.

Can the $14.06 billion, data-center-heavy backlog convert into third-quarter revenue at same-store growth of at least 30% in a seasonally strong quarter, without the backlog itself shrinking?

This question sets how much growth slows in the second half, and the third quarter is the first test. Technology customers were already 58.7% of second-quarter revenue[6], and management's full-year 2026 same-store growth guidance moved from "mid to high teens" in February[23] to "mid to high 20%" in April[44] and "mid to high 30%" in July[4]. The third quarter is both the first quarter for judging the second-half slowdown and the first full quarter of Hunt, which closed on May 1[14].

The evidence for continued conversion is direct, but the alternative reading also has support. Second-quarter revenue grew 50.3%[2], and backlog rose 12.9% sequentially to $14.06 billion, with same-store additions of $1.39 billion driven mainly by $1.00 billion at the Texas electrical operation and $510.2 million at the Texas modular operation[7]; management said core hyperscaler customers show no sign of slowing construction and that all modular expansion is tied to committed customer volume[37]. On the other hand, mechanical same-store growth in the second quarter was concentrated in a few operations in Texas, Indiana and North Carolina[43], modular backlog is stretching further out[37], backlog growing faster than revenue does not necessarily mean third-quarter revenue will accelerate, and management itself flagged slower second-half growth[4].

The numeric baselines for this debate are second-quarter revenue of $3,265.7 million and same-store growth of 43.8%[2], technology revenue of $1,917.4 million[6] and June 30 backlog of $14,061.5 million[7]. The transmission runs from data center construction plans at hyperscalers, frontier AI labs and co-location providers to HVAC, process piping, electrical and modular contracts; those contracts enter backlog, are recognized as mechanical and electrical segment revenue as work progresses, and revenue growth then lifts operating profit through SG&A leverage. The constraints are field labor and equipment deliveries, which govern how fast backlog converts rather than how large it is.

What remains unresolved is whether backlog growth reflects work deferred by labor limits or demand that is still expanding. In the third quarter, the items to watch are whether revenue is at least $3.4 billion and same-store growth at least 30%, whether technology revenue reaches $2 billion and holds a share near 58%, whether September 30 backlog is at least $14.06 billion with additions still coming mainly from Texas electrical and modular work, and whether management keeps its "mid to high 30%" full-year guidance. Conversely, a sequential revenue decline or same-store growth below 25%, a sequential backlog decline with the 10-Q citing technology completions outpacing bookings, or a cut to full-year guidance would each indicate that conversion or bookings are slowing.

How much of the roughly 26% gross margin comes from upward estimate revisions as older projects close out, and can the third quarter hold 25.2% without that contribution rising further?

Margin quality directly sets how sensitive profit is, because most of the company's contracts carry a fixed price. On second-quarter revenue, each percentage point of gross margin is worth about $33 million of quarterly gross profit; if a fixed-price cost estimate proves wrong and cannot be recovered through change orders, the result is lower profit or even a loss[18]. Estimate changes are recognized on a cumulative catch-up basis in the quarter they become known[39], and in the first half of 2026 such upward revisions contributed 7.9% of revenue[9], making them one of the main sources of earnings upside.

Evidence of better execution and evidence of one-time gains exist side by side. Second-quarter mechanical gross margin rose from 22.9% to 25.6%, and electrical margin rose about 1 percentage point to 26.4%[19]; the 10-Q attributes the improvement to better execution across numerous operating locations[8], and management said the work it takes is more uniform and repeatable and that it selects projects based on labor and capacity[29]. The alternative reading is that 7.7% of second-quarter revenue came from upward revisions on earlier-period projects, versus 4.4% a year earlier[9] and just 3.9% for full-year 2025[10], and the first quarter also carried about $43.1 million of change-order gains[28]; if those revisions reflect a wave of data center projects reaching closeout, gross margin would drift back toward about 24% as new projects enter early construction.

The numeric baselines for this debate are second-quarter gross margin of 25.9%[8], an estimate-change contribution of 7.7% of revenue[9], and segment gross margins of 25.6% for mechanical and 26.4% for electrical[16]. The transmission starts with cost estimates and contract prices at bid, runs through labor productivity, material deliveries and change orders during construction, produces upward or downward revisions to completion estimates, flows into current-quarter revenue and gross profit through cumulative catch-up, and finally combines with SG&A leverage to set operating margin. The company discloses only the revenue effect of estimate changes, not the gross profit effect, so only the direction and rough size can be judged.

What remains unresolved is how much of the margin expansion comes from pricing on new projects and how much from one-time catch-up on older ones. In the third quarter, the items to watch are whether gross margin is at least 25.2%, whether the estimate-change share of revenue in the 10-Q notes is above or below 7.7%, whether both mechanical and electrical margins exceed their 2025 levels, and whether management's discussion again cites large change orders or one-time gains on individual projects. Gross margin falling back below 24.1%, an estimate-change share above 10% without a higher margin, or mechanical margin below 23.5% would each indicate that margin rests on one-time catch-up rather than pricing on new work.

Second-quarter free cash flow of about $1 billion rested largely on advance billings from big orders; as those prepayments start to be worked down and modular plant purchases continue, can third-quarter operating cash flow still match net income?

Cash flow decides whether the company can expand capacity, make acquisitions and raise dividends at the same time without borrowing. It plans to invest in modular plants at about 5% of revenue[4], keeps buying electrical contractors, with Hunt alone carrying a preliminary price of $206.0 million[14], and has raised the quarterly dividend from $0.80 to $0.90[15]. A meaningful share of the $1.855 billion of cash at the end of June is, in substance, customer prepayments for work not yet performed.

Management's explanation and the long-term record support healthy cash flow, but the balance sheet allows another reading. Second-quarter operating cash flow was $1.139 billion and free cash flow $999.3 million, with first-half free cash flow of $1.242 billion[11]; management said the result partly reflects advance billings on large orders received over the past couple of years, plus strong payment terms and on-time performance that encourage prompt payment, and was not driven by a one-off item[37], and the company has generated positive free cash flow for 27 consecutive years[34]. On the other hand, contract liabilities rose about $1.11 billion in six months[12]; that cash corresponds to work not yet performed and will be absorbed as revenue as construction proceeds, so if prepayments on new large orders slow, operating cash flow will run below profit for a period, while capital spending has already moved from a 2025 baseline of about 1.7% of revenue[45] to about 5%.

The numeric baselines for this debate are second-quarter operating cash flow of $1,139.4 million[11], June 30 contract liabilities of $3,231.1 million[12], second-quarter capital expenditures of $141.4 million[16] and more than 3.5 million square feet of dedicated modular capacity[15]. The transmission runs from advance payments and early billing on large data center orders, which raise contract liabilities and lift operating cash flow above net income; as construction proceeds, prepayments become revenue and contract liabilities fall; modular expansion requires plant and equipment purchases, which raise capital expenditures and reduce free cash flow, and the new capacity then converts modular backlog into revenue.

What remains unresolved is how much of the second-quarter cash flow will reverse in later quarters. In the third quarter, the items to watch are whether operating cash flow is at least equal to net income, whether September 30 contract liabilities stay above $3.231 billion, whether year-to-date capital expenditures fall between 4% and 6% of revenue, and whether management reaffirms more than 4 million square feet of capacity by year-end. Operating cash flow below net income attributed to lower prepayments, a decline of more than 10% in contract liabilities, or capital spending above plan without customer commitments would each indicate that cash flow has entered a payback phase.

Risks and Falsifiers

Labor and material costs are the first risk, and they can slow revenue conversion and compress gross margin at the same time. The 10-Q says labor costs keep rising and some materials and equipment face intermittent shortages and delivery delays, which the company addresses by ordering earlier, reflecting the challenges in pricing and sharing supply risk with customers[40]; first-quarter headcount was 3,000 to 4,000 higher than a year earlier, and materials and equipment rose by a couple hundred basis points as a share of revenue[42]. The exposure sits in cost of services and SG&A: second-quarter cost of services was $2.421 billion[16], and same-store SG&A included $49.1 million of higher compensation[30]. If the outlook section of the third-quarter 10-Q adds no new language on supply chain or labor shortages, and gross margin and revenue both meet their thresholds, this concern would ease.

Customer and geographic concentration is the second risk, because the timing of a few locations and a few customers directly sets quarterly results. Technology customers made up 57.6% of first-half revenue[6]; within second-quarter mechanical same-store growth, one Texas operation contributed $219.4 million, one Indiana operation $123.6 million and one North Carolina operation $115.5 million, while electrical same-store growth came mainly from $186.6 million at the Texas electrical operation[43]; the core customers named on the call are hyperscalers, and the company does not disclose single-customer revenue[15]. If third-quarter same-store growth in the 10-Q spreads across more operating locations or more end markets, and technology revenue growth no longer depends on a single location, this risk would weaken.

Data center construction timing and local policy are the third risk. Several states have begun discussing limits on data centers or on their access to power; on the first-quarter call, management said no states where it operates have such proposals and that demand still exceeds supply[42]; but of the $1.39 billion same-store sequential backlog increase in the second quarter, $1.51 billion came from two Texas operations, partly offset by project completions in North Carolina[7], so a delay by one large customer or in one state would show up directly in quarterly revenue and backlog. The exposure is the $1.917 billion of second-quarter technology revenue; if September 30 backlog is at least $14.06 billion and the 10-Q reports no cancellations or delays of technology projects, the current reading still holds.

Cost risk on fixed-price contracts is the fourth risk, and the larger and more concentrated the projects, the bigger the hit from a downward revision on any one of them. Most projects carry a fixed price, so weaker labor productivity, late equipment deliveries or poor subcontractor performance that cannot be recovered through change orders can reduce profit or cause losses[18], recognized on a cumulative catch-up basis in the quarter they become known[39]. On second-quarter revenue of $3.27 billion, each percentage point of gross margin lost removes about $33 million of quarterly gross profit, and a return of the estimate-change share from 7.7% to 3.9% would remove roughly $120 million of quarterly catch-up revenue support. If the third-quarter 10-Q discloses no loss provisions or downward estimate revisions and gross margin is at least 25.2%, this risk has not materialized.

Reversal of prepayments is the fifth risk, and it can weaken cash flow even when profit holds. The $3.231 billion of contract liabilities corresponds to unfinished work[12] and turns into revenue without new cash as construction proceeds; if payment terms on new large orders worsen or their pace slows, operating cash flow will fall below net income while capital spending on modular plants is already committed[4]. Each 10% decline in contract liabilities removes about $320 million of operating cash flow, and 2026 capital spending planned at about 5% of revenue far exceeds the $154.9 million spent in 2025. If September 30 contract liabilities are at least $3.231 billion and third-quarter operating cash flow is at least equal to net income, this risk has not yet appeared.

What to Watch Next

The third-quarter report and the 10-Q that follows are the first checkpoint for all three debates:

• Backlog conversion: third-quarter revenue of at least $3.4 billion and same-store growth of at least 30%, against $3.27 billion and 43.8% in the second quarter; a sequential revenue decline or same-store growth below 25% would falsify the current reading.
• Backlog size: September 30 backlog of at least $14.06 billion, with additions still led by Texas electrical and modular work; a sequential decline with the 10-Q citing technology completions outpacing bookings would falsify it.
• Technology revenue and guidance: technology revenue reaching $2 billion from $1.917 billion (58.7% of revenue), and the "mid to high 30%" full-year same-store guidance maintained; a guidance cut would falsify it.
• Margin quality: gross margin of at least 25.2% against 25.9%, and the estimate-change share of revenue compared with 7.7%; margin below 24.1%, or an estimate-change share above 10% without a higher margin, would falsify it.
• Segment margins: mechanical at 25.6% and electrical at 26.4%, each checked against its 2025 level; mechanical margin below 23.5% would falsify it.
• Cash flow and contract liabilities: operating cash flow at least equal to net income, against $1.139 billion in the second quarter, and contract liabilities held at $3.231 billion; cash flow below net income attributed to lower prepayments, or a contract-liability decline of more than 10%, would falsify it.
• Capital spending and modular capacity: year-to-date capital expenditures at 4%–6% of revenue, against $141.4 million in the second quarter, and a reaffirmed target of more than 4 million square feet by year-end from more than 3.5 million today; spending above plan without customer commitments would falsify it.

Conclusion

Comfort Systems USA's results are driven by three linked lines: how fast a data-center-heavy backlog converts into revenue, the gross margin produced by executing fixed-price contracts, and cash flow supported by prepayments on large orders. In the second quarter of 2026, revenue rose 50.3% to $3.27 billion, gross margin was 25.9%, backlog stood at $14.06 billion, and the company held $1.855 billion of cash against only $54.1 million of total debt at the end of June[3][34]. The central unresolved relationship is how much of the revenue growth, margin expansion and exceptional cash flow comes from durable new orders and pricing, and how much from estimate revisions at project closeout and customer prepayments for work not yet done.

Since the second-quarter report, the only independent assessment whose text could be verified word for word is a September 10 piece by Zacks Equity Research analyst Shrabana Mukherjee. It argued that the 12.4% three-month share price decline reflected weaker sentiment rather than deteriorating operations, pointing to 50.3% second-quarter revenue growth, a record backlog with 65%–75% to be recognized within 12 months and modular expansion backed by multiyear customer commitments; it also warned that with technology near 58% of first-half revenue, any slowdown in data center spending would have a larger effect than before, and that fast modular expansion, a much larger backlog, higher labor costs and supply shortages all raise execution demands[46]. That outside interpretation lines up with the first debate on backlog conversion and with the modular expansion question in the third debate, but it does not address the estimate-change contribution to gross margin or separate the prepayment component of operating cash flow, so it offers no independent view on the second debate or on cash flow quality. Other material from the same period consisted mostly of rating-change notes or holdings disclosures, so outside coverage is thin and should not be read as a market consensus.

The combination that would most strengthen the current understanding is third-quarter revenue of at least $3.4 billion with same-store growth of at least 30%, September backlog of at least $14.06 billion, gross margin of at least 25.2% without a rising estimate-change share, and operating cash flow at least equal to net income with contract liabilities held above $3.231 billion. Conversely, a sequential decline in revenue or backlog, gross margin falling back below 24.1%, or operating cash flow dropping below profit because of lower prepayments while capital spending continues at about 5% of revenue would materially weaken the current understanding of growth quality and cash flow.

Sources

[1] Drillr earnings calendar · FIX earnings call scheduled 2026-10-22 (calendar last updated 2026-09-23) · 2026-09-23 · Drillr earnings calendar

[2] FIX 10-Q filed 2026-07-23 · 2Q26 revenue, same-store and acquisition contribution · 2026-07-23 · 10-Q · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-Q&dateb=&owner=include&count=40

[3] FIX 8-K filed 2026-07-23 · 2Q26 results press release · 2026-07-23 · 8-K · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=8-K&dateb=&owner=include&count=40

[4] FIX 2Q26 earnings call 2026-07-24 · Drillr structured summary · full-year 2026 guidance · 2026-07-24 · earnings-call · https://ir.comfortsystemsusa.com/

[5] Drillr earnings calendar (updated 2026-09-23) · FIX 2026-10-22 call and 3Q26 estimates · 2026-09-23 · Drillr earnings calendar · https://gateway.drillr.ai/mcp/private

[6] FIX 10-Q filed 2026-07-23 · 2Q26 revenue by customer type and activity type · 2026-07-23 · 10-Q · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-Q&dateb=&owner=include&count=40

[7] FIX 10-Q filed 2026-07-23 · backlog June 30, 2026 and bookings by operation · 2026-07-23 · 10-Q · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-Q&dateb=&owner=include&count=40

[8] FIX 10-Q filed 2026-07-23 · 2Q26 gross profit · 2026-07-23 · 10-Q · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-Q&dateb=&owner=include&count=40

[9] FIX 10-Q filed 2026-07-23 · 2Q26 changes in estimates on partially satisfied performance obligations · 2026-07-23 · 10-Q · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-Q&dateb=&owner=include&count=40

[10] FIX 10-K filed 2026-02-19 · changes in estimates on partially satisfied performance obligations · 2026-02-19 · 10-K · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-K&dateb=&owner=include&count=40

[11] FIX 8-K filed 2026-07-23 · 2Q26 cash flow and free cash flow · 2026-07-23 · 8-K · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=8-K&dateb=&owner=include&count=40

[12] FIX 10-Q filed 2026-07-23 · contract assets and liabilities June 30, 2026 · 2026-07-23 · 10-Q · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-Q&dateb=&owner=include&count=40

[13] FIX 10-K filed 2026-02-19 · FY2025 revenue growth, same-store and data centers · 2026-02-19 · 10-K · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-K&dateb=&owner=include&count=40

[14] FIX 10-Q filed 2026-07-23 · Hunt acquisition · 2026-07-23 · 10-Q · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-Q&dateb=&owner=include&count=40

[15] FIX 2Q26 earnings call 2026-07-24 · Drillr structured summary · management highlights, backlog and modular capacity · 2026-07-24 · earnings-call · https://ir.comfortsystemsusa.com/

[16] FIX 10-Q filed 2026-07-23 · 2Q26 and 2Q25 segment results · 2026-07-23 · 10-Q · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-Q&dateb=&owner=include&count=40

[17] FIX 10-Q filed 2026-07-23 · project-based revenue and bidding · 2026-07-23 · 10-Q · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-Q&dateb=&owner=include&count=40

[18] FIX 10-K filed 2026-02-19 · fixed-price contracts, change orders and retainage · 2026-02-19 · 10-K · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-K&dateb=&owner=include&count=40

[19] FIX 2Q26 earnings call 2026-07-24 · Drillr structured summary · segment performance and 2Q26 mix · 2026-07-24 · earnings-call · https://ir.comfortsystemsusa.com/

[20] FIX 10-K filed 2026-02-19 · modular construction and service growth strategy · 2026-02-19 · 10-K · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-K&dateb=&owner=include&count=40

[21] FIX 10-K filed 2026-02-19 · FY2023-2025 segment revenue, gross profit and operating income · 2026-02-19 · 10-K · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-K&dateb=&owner=include&count=40

[22] FIX 10-K filed 2026-02-19 · FY2025 gross profit and SG&A · 2026-02-19 · 10-K · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-K&dateb=&owner=include&count=40

[23] FIX 4Q25 earnings call 2026-02-20 · Drillr structured summary · guidance and 2025 mix · 2026-02-20 · earnings-call · https://ir.comfortsystemsusa.com/

[24] FIX 10-K filed 2026-02-19 · FY2025 mechanical and electrical revenue drivers · 2026-02-19 · 10-K · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-K&dateb=&owner=include&count=40

[25] FIX 10-K filed 2026-02-19 · FY2025 operating cash flow drivers and seasonality · 2026-02-19 · 10-K · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-K&dateb=&owner=include&count=40

[26] FIX 10-K filed 2026-02-19 · backlog December 31, 2025 · 2026-02-19 · 10-K · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-K&dateb=&owner=include&count=40

[27] FIX 10-Q filed 2026-04-23 · 1Q26 results of operations · 2026-04-23 · 10-Q · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-Q&dateb=&owner=include&count=40

[28] FIX 10-Q filed 2026-07-23 · 1H26 gross profit and 1Q26 change orders · 2026-07-23 · 10-Q · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-Q&dateb=&owner=include&count=40

[29] FIX 1Q26 earnings call 2026-04-24 · Drillr structured summary · Q&A on change orders and margin sustainability · 2026-04-24 · earnings-call · https://ir.comfortsystemsusa.com/

[30] FIX 10-Q filed 2026-07-23 · 2Q26 SG&A and labor cost · 2026-07-23 · 10-Q · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-Q&dateb=&owner=include&count=40

[31] FIX 8-K filed 2026-07-23 · 2Q26 adjusted EBITDA reconciliation · 2026-07-23 · 8-K · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=8-K&dateb=&owner=include&count=40

[32] FIX 10-Q filed 2026-04-23 · 1Q26 modular building purchase and capex outlook · 2026-04-23 · 10-Q · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-Q&dateb=&owner=include&count=40

[33] FIX 8-K filed 2026-07-23 · condensed balance sheet June 30, 2026 · 2026-07-23 · 8-K · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=8-K&dateb=&owner=include&count=40

[34] FIX 8-K filed 2026-08-03 · August 2026 investor presentation · 2026-08-03 · 8-K · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=8-K&dateb=&owner=include&count=40

[35] FIX 10-Q filed 2026-07-23 · 1H26 cash flow statement · 2026-07-23 · 10-Q · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-Q&dateb=&owner=include&count=40

[36] FIX 10-Q filed 2026-07-23 · remaining performance obligations June 30, 2026 · 2026-07-23 · 10-Q · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-Q&dateb=&owner=include&count=40

[37] FIX 2Q26 earnings call 2026-07-24 · Drillr structured summary · Q&A on advance billings, backlog duration and modular returns · 2026-07-24 · earnings-call · https://ir.comfortsystemsusa.com/

[38] FIX 10-Q filed 2026-07-23 · cyclicality and seasonality · 2026-07-23 · 10-Q · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-Q&dateb=&owner=include&count=40

[39] FIX 10-K filed 2026-02-19 · estimate-at-completion and cumulative catch-up policy · 2026-02-19 · 10-K · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-K&dateb=&owner=include&count=40

[40] FIX 10-Q filed 2026-07-23 · outlook, labor costs and supply chain · 2026-07-23 · 10-Q · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-Q&dateb=&owner=include&count=40

[41] FIX 10-K filed 2026-02-19 · skilled labor scarcity and workforce utilization · 2026-02-19 · 10-K · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-K&dateb=&owner=include&count=40

[42] FIX 1Q26 earnings call 2026-04-24 · Drillr structured summary · Q&A on labor, headcount and data-center legislation · 2026-04-24 · earnings-call · https://ir.comfortsystemsusa.com/

[43] FIX 10-Q filed 2026-07-23 · 2Q26 mechanical and electrical revenue drivers · 2026-07-23 · 10-Q · https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001035983&type=10-Q&dateb=&owner=include&count=40

[44] FIX 1Q26 earnings call 2026-04-24 · Drillr structured summary · guidance and revenue mix · 2026-04-24 · earnings-call · https://ir.comfortsystemsusa.com/

[45] FIX 4Q25 earnings call 2026-02-20 · Drillr structured summary · Q&A on backlog, modular bookings and labor · 2026-02-20 · earnings-call · https://ir.comfortsystemsusa.com/

[46] Zacks Equity Research 2026-09-10 · Comfort Systems Stock Plunges 12.4% in 3 Months: Buy the Dip? · 2026-09-10 · Zacks Equity Research · https://finance.yahoo.com/markets/stocks/articles/comfort-systems-stock-plunges-12-165200189.html