Source: Comfort Systems USA Form 10-Q and Form 10-K MD&A operating segment backlog table (in thousands). Q1 2025 Mechanical $5,205,745 / Electrical $1,683,073: https://www.sec.gov/Archives/edgar/data/1035983/000155837025005411/fix-20250331x10q.htm. Q2 2025 $5,814,217 / $2,309,491: https://www.sec.gov/Archives/edgar/data/1035983/000155837025009536/fix-20250630x10q.htm. Q3 2025 $6,790,316 / $2,586,522: https://www.sec.gov/Archives/edgar/data/1035983/000110465925101821/fix-20250930x10q.htm. Q4 2025 $9,026,661 / $2,917,940: Form 10-K year ended 31 Dec 2025 https://www.sec.gov/Archives/edgar/data/1035983/000110465926017530/fix-20251231x10k.htm. Q1 2026 $9,593,241 / $2,861,485: https://www.sec.gov/Archives/edgar/data/1035983/000110465926047689/fix-20260331x10q.htm. Q2 2026 $10,058,662 / $4,002,847: https://www.sec.gov/Archives/edgar/data/1035983/000110465926086258/fix-20260630x10q.htm. Q3 2026 $12,204,936 / $5,609,906: https://www.sec.gov/Archives/edgar/data/1035983/000110465926118159/fix-20260930x10q.htm.

Source: Comfort Systems USA Form 10-Q and Form 10-K MD&A backlog table (dollars in thousands) and Note 3 remaining construction performance obligations (same printed total). Q3 2021 MD&A backlog year-ago thousands 1,941,377 (https://www.sec.gov/Archives/edgar/data/1035983/000155837022015407/fix-20220930x10q.htm). Q4 2021 MD&A backlog prior year-end thousands 2,311,884 (https://www.sec.gov/Archives/edgar/data/1035983/000155837022015407/fix-20220930x10q.htm). Q1 2022 MD&A backlog year-ago thousands 2,732,976 (https://www.sec.gov/Archives/edgar/data/1035983/000155837023006827/fix-20230331x10q.htm). Q2 2022 MD&A backlog year-ago thousands 2,807,772 (https://www.sec.gov/Archives/edgar/data/1035983/000155837023012288/fix-20230630x10q.htm). Q3 2022 MD&A backlog year-ago thousands 3,250,536 (https://www.sec.gov/Archives/edgar/data/1035983/000155837023016855/fix-20230930x10q.htm). Q4 2022 MD&A backlog prior year-end thousands 4,063,743 (https://www.sec.gov/Archives/edgar/data/1035983/000155837023016855/fix-20230930x10q.htm). Q1 2023 MD&A backlog year-ago thousands 4,444,944 (https://www.sec.gov/Archives/edgar/data/1035983/000155837024005763/fix-20240331x10q.htm). Q2 2023 MD&A backlog year-ago thousands 4,185,533 (https://www.sec.gov/Archives/edgar/data/1035983/000155837024010178/fix-20240630x10q.htm). Q3 2023 MD&A backlog year-ago thousands 4,287,586 (https://www.sec.gov/Archives/edgar/data/1035983/000155837024013635/fix-20240930x10q.htm). Q4 2023 MD&A backlog prior year-end thousands 5,157,376 (https://www.sec.gov/Archives/edgar/data/1035983/000155837024013635/fix-20240930x10q.htm). Q1 2024 MD&A backlog year-ago thousands 5,911,648 (https://www.sec.gov/Archives/edgar/data/1035983/000155837025005411/fix-20250331x10q.htm). Q2 2024 MD&A backlog year-ago thousands 5,772,220 (https://www.sec.gov/Archives/edgar/data/1035983/000155837025009536/fix-20250630x10q.htm). Q3 2024 MD&A backlog year-ago thousands 5,680,781 (https://www.sec.gov/Archives/edgar/data/1035983/000110465925101821/fix-20250930x10q.htm). Q4 2024 MD&A backlog prior year-end thousands 5,993,966 (https://www.sec.gov/Archives/edgar/data/1035983/000110465925101821/fix-20250930x10q.htm). Q1 2025 MD&A backlog year-ago thousands 6,888,818 (https://www.sec.gov/Archives/edgar/data/1035983/000110465926047689/fix-20260331x10q.htm). Q2 2025 MD&A backlog year-ago thousands 8,123,708 (https://www.sec.gov/Archives/edgar/data/1035983/000110465926086258/fix-20260630x10q.htm). Q3 2025 MD&A backlog thousands 9,376,838 (https://www.sec.gov/Archives/edgar/data/1035983/000110465925101821/fix-20250930x10q.htm). Q4 2025 MD&A backlog prior year-end thousands 11,944,601 (https://www.sec.gov/Archives/edgar/data/1035983/000110465926086258/fix-20260630x10q.htm). Q1 2026 MD&A backlog thousands 12,454,726 (https://www.sec.gov/Archives/edgar/data/1035983/000110465926047689/fix-20260331x10q.htm). Q2 2026 MD&A backlog thousands 14,061,509 (https://www.sec.gov/Archives/edgar/data/1035983/000110465926086258/fix-20260630x10q.htm). Q3 2026 MD&A backlog thousands 17,814,842 and Note 3 remaining performance obligations $17.81 billion (https://www.sec.gov/Archives/edgar/data/1035983/000110465926118159/fix-20260930x10q.htm)

Source: Comfort Systems USA Note 3 Revenue from Contracts with Customers, Revenue by Activity Type (dollars in thousands). Q1 2025: https://www.sec.gov/Archives/edgar/data/1035983/000155837025005411/fix-20250331x10q.htm. Q2 2025: https://www.sec.gov/Archives/edgar/data/1035983/000155837025009536/fix-20250630x10q.htm. Q3 2025: https://www.sec.gov/Archives/edgar/data/1035983/000110465925101821/fix-20250930x10q.htm. Q4 2025 = Form 10-K year ended 31 Dec 2025 minus nine months ended 30 Sep 2025: 10-K https://www.sec.gov/Archives/edgar/data/1035983/000110465926017530/fix-20251231x10k.htm and Q3 2025 10-Q https://www.sec.gov/Archives/edgar/data/1035983/000110465925101821/fix-20250930x10q.htm. Q1 2026: https://www.sec.gov/Archives/edgar/data/1035983/000110465926047689/fix-20260331x10q.htm. Q2 2026: https://www.sec.gov/Archives/edgar/data/1035983/000110465926086258/fix-20260630x10q.htm. Q3 2026: https://www.sec.gov/Archives/edgar/data/1035983/000110465926118159/fix-20260930x10q.htm.

Source: Comfort Systems USA Form 10-Q MD&A Revenue paragraph (reported % increase, same-store activity %, acquisition %). Q1 2025 19.1 / 15.4 / 3.7: https://www.sec.gov/Archives/edgar/data/1035983/000155837025005411/fix-20250331x10q.htm. Q2 2025 20.1 / 18.6 / 1.5: https://www.sec.gov/Archives/edgar/data/1035983/000155837025009536/fix-20250630x10q.htm. Q3 2025 35.2 / 33.3 / 1.9: https://www.sec.gov/Archives/edgar/data/1035983/000110465925101821/fix-20250930x10q.htm. Q4 2025 reported 41.7% from Form 8-K Exhibit 99.1 revenue $2,646,067 thousand vs $1,867,804 thousand https://www.sec.gov/Archives/edgar/data/1035983/000110465926017529/fix-20260219xex99d1.htm. Q4 2025 same-store 35% from Q4 2025 earnings conference call, 20 Feb 2026 (https://stockanalysis.com/stocks/fix/transcripts/402870-q4-2025/). Acquisition points not printed for Q4. Q1 2026 56.5 / 51.5 / 5.0: https://www.sec.gov/Archives/edgar/data/1035983/000110465926047689/fix-20260331x10q.htm. Q2 2026 50.3 / 43.8 / 6.5: https://www.sec.gov/Archives/edgar/data/1035983/000110465926086258/fix-20260630x10q.htm. Q3 2026 53.7 / 46.3 / 7.4: https://www.sec.gov/Archives/edgar/data/1035983/000110465926118159/fix-20260930x10q.htm.

Source: Comfort Systems USA Form 10-Q MD&A Revenue paragraph (same-store activity %). 10-K prints annual same-store only and is not used as a Q4 point. Q4 2025 35% is the Q4 2025 earnings conference call prepared remarks (https://stockanalysis.com/stocks/fix/transcripts/402870-q4-2025/). Q2 2020 MD&A quarterly same-store 2.1 (https://www.sec.gov/Archives/edgar/data/1035983/000155837020008436/fix-20200630x10q.htm). Q3 2020 MD&A quarterly same-store -5.8 (https://www.sec.gov/Archives/edgar/data/1035983/000155837020011739/fix-20200930x10q.htm). Q1 2021 MD&A quarterly same-store -11.8 (https://www.sec.gov/Archives/edgar/data/1035983/000155837021005084/fix-20210331x10q.htm). Q2 2021 MD&A quarterly same-store -6.2 (https://www.sec.gov/Archives/edgar/data/1035983/000155837021009480/fix-20210630x10q.htm). Q3 2021 MD&A quarterly same-store 8.8 (https://www.sec.gov/Archives/edgar/data/1035983/000155837021013631/fix-20210930x10q.htm). Q1 2022 MD&A quarterly same-store 15.6 (https://www.sec.gov/Archives/edgar/data/1035983/000155837022006108/fix-20220331x10q.htm). Q2 2022 MD&A quarterly same-store 24.7 (https://www.sec.gov/Archives/edgar/data/1035983/000155837022011139/fix-20220630x10q.htm). Q3 2022 MD&A quarterly same-store 22.7 (https://www.sec.gov/Archives/edgar/data/1035983/000155837022015407/fix-20220930x10q.htm). Q1 2023 MD&A quarterly same-store 30 (https://www.sec.gov/Archives/edgar/data/1035983/000155837023006827/fix-20230331x10q.htm). Q2 2023 MD&A quarterly same-store 24.2 (https://www.sec.gov/Archives/edgar/data/1035983/000155837023012288/fix-20230630x10q.htm). Q3 2023 MD&A quarterly same-store 20 (https://www.sec.gov/Archives/edgar/data/1035983/000155837023016855/fix-20230930x10q.htm). Q1 2024 MD&A quarterly same-store 22.7 (https://www.sec.gov/Archives/edgar/data/1035983/000155837024005763/fix-20240331x10q.htm). Q2 2024 MD&A quarterly same-store 29.5 (https://www.sec.gov/Archives/edgar/data/1035983/000155837024010178/fix-20240630x10q.htm). Q3 2024 MD&A quarterly same-store 17.5 (https://www.sec.gov/Archives/edgar/data/1035983/000155837024013635/fix-20240930x10q.htm). Q1 2025 MD&A quarterly same-store 15.4 (https://www.sec.gov/Archives/edgar/data/1035983/000155837025005411/fix-20250331x10q.htm). Q2 2025 MD&A quarterly same-store 18.6 (https://www.sec.gov/Archives/edgar/data/1035983/000155837025009536/fix-20250630x10q.htm). Q3 2025 MD&A quarterly same-store 33.3 (https://www.sec.gov/Archives/edgar/data/1035983/000110465925101821/fix-20250930x10q.htm). Q4 2025 Q4 2025 earnings call (10-K prints annual same-store only) 35 (https://stockanalysis.com/stocks/fix/transcripts/402870-q4-2025/). Q1 2026 MD&A quarterly same-store 51.5 (https://www.sec.gov/Archives/edgar/data/1035983/000110465926047689/fix-20260331x10q.htm). Q2 2026 MD&A quarterly same-store 43.8 (https://www.sec.gov/Archives/edgar/data/1035983/000110465926086258/fix-20260630x10q.htm). Q3 2026 MD&A quarterly same-store 46.3 (https://www.sec.gov/Archives/edgar/data/1035983/000110465926118159/fix-20260930x10q.htm)

Source: Comfort Systems USA Note 3 Revenue from Contracts with Customers, Revenue by Type of Customer (dollars in thousands). Q1 2022 Note 3 Technology year-ago three-month 95,455 (https://www.sec.gov/Archives/edgar/data/1035983/000155837023006827/fix-20230331x10q.htm). Q2 2022 Note 3 Technology year-ago three-month 132,078 (https://www.sec.gov/Archives/edgar/data/1035983/000155837023012288/fix-20230630x10q.htm). Q3 2022 Note 3 Technology year-ago three-month 165,717 (https://www.sec.gov/Archives/edgar/data/1035983/000155837023016855/fix-20230930x10q.htm). Q4 2022 10-K FY 546290 minus Q3 9M 393250 (https://www.sec.gov/Archives/edgar/data/1035983/000155837023016855/fix-20230930x10q.htm) 153,040 (https://www.sec.gov/Archives/edgar/data/1035983/000155837024001529/fix-20231231x10k.htm). Q1 2023 Note 3 Technology year-ago three-month 226,249 (https://www.sec.gov/Archives/edgar/data/1035983/000155837024005763/fix-20240331x10q.htm). Q2 2023 Note 3 Technology year-ago three-month 265,231 (https://www.sec.gov/Archives/edgar/data/1035983/000155837024010178/fix-20240630x10q.htm). Q3 2023 Note 3 Technology year-ago three-month 303,847 (https://www.sec.gov/Archives/edgar/data/1035983/000155837024013635/fix-20240930x10q.htm). Q4 2023 10-K FY 1114382 minus Q3 9M 795327 (https://www.sec.gov/Archives/edgar/data/1035983/000155837024013635/fix-20240930x10q.htm) 319,055 (https://www.sec.gov/Archives/edgar/data/1035983/000155837025001222/fix-20241231x10k.htm). Q1 2024 Note 3 Technology year-ago three-month 464,814 (https://www.sec.gov/Archives/edgar/data/1035983/000155837025005411/fix-20250331x10q.htm). Q2 2024 Note 3 Technology year-ago three-month 561,313 (https://www.sec.gov/Archives/edgar/data/1035983/000155837025009536/fix-20250630x10q.htm). Q3 2024 Note 3 Technology year-ago three-month 615,398 (https://www.sec.gov/Archives/edgar/data/1035983/000110465925101821/fix-20250930x10q.htm). Q4 2024 10-K FY 2331362 minus Q3 9M 1641525 (https://www.sec.gov/Archives/edgar/data/1035983/000110465925101821/fix-20250930x10q.htm) 689,837 (https://www.sec.gov/Archives/edgar/data/1035983/000110465926017530/fix-20251231x10k.htm). Q1 2025 Note 3 Technology year-ago three-month 677,553 (https://www.sec.gov/Archives/edgar/data/1035983/000110465926047689/fix-20260331x10q.htm). Q2 2025 Note 3 Technology year-ago three-month 934,199 (https://www.sec.gov/Archives/edgar/data/1035983/000110465926086258/fix-20260630x10q.htm). Q3 2025 Note 3 Technology three-month 1,122,528 (https://www.sec.gov/Archives/edgar/data/1035983/000110465925101821/fix-20250930x10q.htm). Q4 2025 10-K FY 4098854 minus Q3 9M 2734280 (https://www.sec.gov/Archives/edgar/data/1035983/000110465925101821/fix-20250930x10q.htm) 1,364,574 (https://www.sec.gov/Archives/edgar/data/1035983/000110465926017530/fix-20251231x10k.htm). Q1 2026 Note 3 Technology three-month 1,616,515 (https://www.sec.gov/Archives/edgar/data/1035983/000110465926047689/fix-20260331x10q.htm). Q2 2026 Note 3 Technology three-month 1,917,354 (https://www.sec.gov/Archives/edgar/data/1035983/000110465926086258/fix-20260630x10q.htm). Q3 2026 Note 3 Technology three-month 2,290,001 (https://www.sec.gov/Archives/edgar/data/1035983/000110465926118159/fix-20260930x10q.htm)