Source: Sterling Form 8-K Exhibit 99.1 Additional Financial Metrics (Backlog, Combined Backlog, Unsigned Awards footnotes) and Form 10-Q / 10-K MD&A Backlog. Q4 2024 Backlog $1.69 billion and Unsigned Awards $137.9 million: Form 10-K year ended 31 Dec 2024 https://www.sec.gov/Archives/edgar/data/874238/000087423825000025/strl-20241231.htm. Q1 2025 Backlog $2.13 billion, Combined $2.23 billion, Unsigned Awards $103.2 million: Q1 2025 earnings release https://www.prnewswire.com/news-releases/sterling-reports-first-quarter-2025-results-and-increases-full-year-guidance-302446320.html (RPO $2,128.405 million in Form 10-Q https://www.sec.gov/Archives/edgar/data/874238/000087423825000069/strl-20250331.htm). Q2 2025 Backlog $2.01 billion, Combined $2.25 billion, Unsigned Awards $237.3 million: Exhibit 99.1 https://www.sec.gov/Archives/edgar/data/874238/000087423825000119/a20250804ex991earningsrele.htm. Q3 2025 Backlog $2.58 billion, Combined $3.44 billion, Unsigned Awards $868.8 million: Exhibit 99.1 https://www.sec.gov/Archives/edgar/data/874238/000087423825000133/a20251103ex991earningsrele.htm. Q4 2025 Backlog $3.01 billion, Combined $3.31 billion, Unsigned Awards $300.7 million: Exhibit 99.1 https://www.sec.gov/Archives/edgar/data/874238/000087423826000018/a20260225ex991earningsrele.htm. Q1 2026 Backlog $3.80 billion, Combined $5.15 billion, Unsigned Awards $1.36 billion: Exhibit 99.1 https://www.sec.gov/Archives/edgar/data/874238/000087423826000052/a20260504ex991earningsrele.htm. Q2 2026 Backlog $4.33 billion, Combined $5.62 billion, Unsigned Awards $1.28 billion: Exhibit 99.1 https://www.sec.gov/Archives/edgar/data/874238/000087423826000100/a20260803ex991earningsrele.htm and Form 10-Q MD&A https://www.sec.gov/Archives/edgar/data/874238/000087423826000103/strl-20260630.htm. Q3 2026 Backlog $4.14 billion, Combined $6.14 billion, Unsigned Awards $2.00 billion: Exhibit 99.1 https://www.sec.gov/Archives/edgar/data/874238/000087423826000122/a20261028ex991earningsrele.htm and Exhibit 99.2 Backlog table https://www.sec.gov/Archives/edgar/data/874238/000087423826000122/q32026earningsrelease_ir.htm.

Source: Sterling Form 10-K and Form 10-Q Revenue from Customers, Remaining Performance Obligations table (USD thousands, converted to billions). Q4 2024 $1,693.223 million: Form 10-K year ended 31 Dec 2024 https://www.sec.gov/Archives/edgar/data/874238/000087423825000025/strl-20241231.htm. Q1 2025 $2,128.405 million: Form 10-Q quarter ended 31 Mar 2025 https://www.sec.gov/Archives/edgar/data/874238/000087423825000069/strl-20250331.htm. Q2 2025 $2,008.695 million: Form 10-Q quarter ended 30 Jun 2025 https://www.sec.gov/Archives/edgar/data/874238/000087423825000122/strl-20250630.htm. Q3 2025 $2,575.370 million: Form 10-Q quarter ended 30 Sep 2025 https://www.sec.gov/Archives/edgar/data/874238/000087423825000136/strl-20250930.htm. Q4 2025 $3,010.942 million: Form 10-K year ended 31 Dec 2025 https://www.sec.gov/Archives/edgar/data/874238/000087423826000024/strl-20251231.htm. Q1 2026 $3,795.754 million: Form 10-Q quarter ended 31 Mar 2026 https://www.sec.gov/Archives/edgar/data/874238/000087423826000055/strl-20260331.htm. Q2 2026 $4,233.618 million: Form 10-Q quarter ended 30 Jun 2026 https://www.sec.gov/Archives/edgar/data/874238/000087423826000103/strl-20260630.htm. Q3 2026 $4.05 billion (rounded): Exhibit 99.2 Backlog footnote https://www.sec.gov/Archives/edgar/data/874238/000087423826000122/q32026earningsrelease_ir.htm (Form 10-Q for the quarter ended 30 Sep 2026 not yet filed).

Source: Sterling Form 10-K and Form 10-Q Revenue from Customers, Remaining Performance Obligations by segment (USD thousands, shown as millions). Q4 2024: Form 10-K year ended 31 Dec 2024 https://www.sec.gov/Archives/edgar/data/874238/000087423825000025/strl-20241231.htm. Q1 2025: Form 10-Q quarter ended 31 Mar 2025 https://www.sec.gov/Archives/edgar/data/874238/000087423825000069/strl-20250331.htm. Q2 2025: Form 10-Q quarter ended 30 Jun 2025 https://www.sec.gov/Archives/edgar/data/874238/000087423825000122/strl-20250630.htm. Q3 2025: Form 10-Q quarter ended 30 Sep 2025 https://www.sec.gov/Archives/edgar/data/874238/000087423825000136/strl-20250930.htm. Q4 2025: Form 10-K year ended 31 Dec 2025 https://www.sec.gov/Archives/edgar/data/874238/000087423826000024/strl-20251231.htm. Q1 2026: Form 10-Q quarter ended 31 Mar 2026 https://www.sec.gov/Archives/edgar/data/874238/000087423826000055/strl-20260331.htm. Q2 2026: Form 10-Q quarter ended 30 Jun 2026 https://www.sec.gov/Archives/edgar/data/874238/000087423826000103/strl-20260630.htm. Q2 2026 contractual Backlog by segment, including $100 million of MSAs in E-Infrastructure: Q2 2026 Exhibit 99.2 Total Backlog table https://www.sec.gov/Archives/edgar/data/874238/000087423826000100/q22026earningsreleaseppp.htm. Q3 2026: Form 10-Q quarter ended 30 Sep 2026, Acc 0000874238-26-000125 https://www.sec.gov/Archives/edgar/data/874238/000087423826000125/strl-20260930.htm (its 31 Dec 2025 comparatives match the Q4 2025 row).

Source: Sterling Form 10-K and Form 10-Q Remaining Performance Obligations footnote (approximately X% of RPOs as revenue during the next 12 months). Q4 2024 74%: Form 10-K year ended 31 Dec 2024 https://www.sec.gov/Archives/edgar/data/874238/000087423825000025/strl-20241231.htm. Q1 2025 80%: Form 10-Q quarter ended 31 Mar 2025 https://www.sec.gov/Archives/edgar/data/874238/000087423825000069/strl-20250331.htm. Q2 2025 78%: Form 10-Q quarter ended 30 Jun 2025 https://www.sec.gov/Archives/edgar/data/874238/000087423825000122/strl-20250630.htm. Q3 2025 70%: Form 10-Q quarter ended 30 Sep 2025 https://www.sec.gov/Archives/edgar/data/874238/000087423825000136/strl-20250930.htm. Q4 2025 64%: Form 10-K year ended 31 Dec 2025 https://www.sec.gov/Archives/edgar/data/874238/000087423826000024/strl-20251231.htm. Q1 2026 70%: Form 10-Q quarter ended 31 Mar 2026 https://www.sec.gov/Archives/edgar/data/874238/000087423826000055/strl-20260331.htm. Q2 2026 74%: Form 10-Q quarter ended 30 Jun 2026 https://www.sec.gov/Archives/edgar/data/874238/000087423826000103/strl-20260630.htm. Q3 2026 72%: Form 10-Q quarter ended 30 Sep 2026, Acc 0000874238-26-000125 https://www.sec.gov/Archives/edgar/data/874238/000087423826000125/strl-20260930.htm.

Source: Sterling Form 8-K Exhibit 99.1 CEO remarks on the legacy site development business (year-over-year revenue growth). Q3 2025 42%: Exhibit 99.1 https://www.sec.gov/Archives/edgar/data/874238/000087423825000133/a20251103ex991earningsrele.htm. Q4 2025 67%: Exhibit 99.1 https://www.sec.gov/Archives/edgar/data/874238/000087423826000018/a20260225ex991earningsrele.htm. Q1 2026 102%: Exhibit 99.1 https://www.sec.gov/Archives/edgar/data/874238/000087423826000052/a20260504ex991earningsrele.htm. Q2 2026 111%: Exhibit 99.1 https://www.sec.gov/Archives/edgar/data/874238/000087423826000100/a20260803ex991earningsrele.htm (presentation also prints 111% excluding CEC and Stone Ridge: https://www.sec.gov/Archives/edgar/data/874238/000087423826000100/q22026earningsreleaseppp.htm). Q3 2026 133%: Exhibit 99.1 E-Infrastructure segment results https://www.sec.gov/Archives/edgar/data/874238/000087423826000122/a20261028ex991earningsrele.htm.