Full year 2020 adjusted net income and adjusted diluted earnings per share, both non-GAAP measures, were $376.4 million, or $5.11 per adjusted diluted share, compared to $415.9 million, or $5.46 per adjusted diluted share during 2019.
Full year 2020 adjusted EBITDA, also a non-GAAP measure, was $810.0 million, compared to $843.2 million in 2019. Full year 2020 adjusted EBITDA margin rate of 12.8% increased 110 basis points compared to last year.
Adjusted net income, adjusted diluted earnings per share, adjusted EBITDA, and free cash flow, which are all non-GAAP measures, exclude certain items which are detailed and reconciled to the most comparable GAAP-reported measures in the attached Supplemental Disclosures and Reconciliation of Non-GAAP Disclosures.
Jose Mas, MasTec’s Chief Executive Officer, commented, “As I reflect on how our team successfully and safely managed unprecedented challenges during 2020, I am incredibly proud of the men and women of MasTec. Our operations have exhibited tremendous resiliency during the pandemic, and as I look forward to 2021 and beyond, I am extremely excited about various significant growth opportunities as we provide critical power, communications and other infrastructure services to our customers.”
Mr. Mas continued, “Our initial 2021 guidance reflects strong 24% revenue growth, with all of our segments expected to approach double digit top line increases when compared to last year. We also expect our non-Oil & Gas segments to experience approximately 40% adjusted EBITDA dollar growth in 2021, continuing the trend we experienced in 2020, highlighting the strength of our diversified portfolio of services. We expect 2021 will be a record year, with developing trends in communications, clean energy and infrastructure affording us strong opportunities for additional growth in 2022 and beyond.”
George Pita, MasTec’s Executive Vice President and Chief Financial Officer, noted, “During 2020, despite the impacts of the pandemic, we maintained a strong cash flow profile, with record annual 2020 cash flow from operations of $937 million and 2020 annual free cash flow exceeding adjusted net income by over $380 million. Our strong cash flow performance allowed us to reduce our 2020 year-end net debt level by approximately $481 million when compared to last year, the lowest level in over 7 years. We enter the new year with a strong balance sheet, ample liquidity and comfortable leverage metrics, providing us the financial ability to take advantage of various opportunities our markets afford us to maximize shareholder value.”
While the nation continues to be affected by the COVID-19 pandemic, most of MasTec’s construction services have been deemed essential under state and local pandemic mitigation orders, and all its business segments have continued to operate. The COVID-19 pandemic has had a negative impact on the Company’s operations and the Company expects some continued negative impact. Negative effects include lost productivity from governmental permitting approval delays, reduced crew productivity due to social distancing, other mitigation measures or other factors, the health and availability of work crews or other key personnel, including subcontractors or supply chain disruptions, and/or delayed project start dates or project shutdowns or cancellations that may be mandated or requested by governmental authorities or others, all of which could result in lower revenue, higher operating costs and/or create lower levels of overhead cost absorption.
Based on the information available today, the Company is providing both first quarter and full year 2021 guidance. The Company currently expects full year 2021 revenue will approximate $7.8 billion, a record level. 2021 full year GAAP net income and diluted earnings per share are expected to approximate $321 million and $4.34, respectively. Full year 2021 adjusted EBITDA and adjusted diluted earnings per share are expected to approximate $875 million, representing a record level, or 11.2% of revenue, and adjusted diluted earnings per share expected to be $5.00.
For the first quarter of 2021, the Company expects revenue of approximately $1.65 billion. First quarter 2021 GAAP net income is expected to approximate $47 million, with GAAP diluted earnings per share expected to be $0.64. First quarter 2021 adjusted EBITDA is expected to approximate $172 million or 10.4% of revenue, with adjusted diluted earnings per share expected to be $0.80.