Jay Johnson
Analyst · those discussed in this call in the company's first quarter 2021 earnings release and its most recent annual report on Form 10-K. Lamar refers you to those documents.
Lamar's first quarter 2021 earnings release, which contains information required by Regulation G regarding certain non-GAAP financial measures was furnished to the SEC on a Form 8-K this morning and is available on the Investors section of Lamar's website at www.lamar.com.
I would now like to turn the conference over to Sean Reilly. Mr. Reilly, you may begin
Thanks, Sean. Good morning, everyone, and thank you for joining us. I will begin with brief comments on the quarter, then review our balance sheet and conclude with a discussion of our current financial position, including a little more detail around this morning's revised guidance.
We had a solid first quarter, exceeding internal expectations across revenue, adjusted EBITDA and AFFO. We had year-over-year AFFO growth for the second consecutive quarter, improving 2.7% to $1.15 per share on a fully diluted basis against Q1 2020. In the first quarter, acquisition-adjusted revenue declined 8.2% from the same period last year.
As you may recall, we began 2020 strong in January and February prior to the onset of the COVID-19 pandemic. As a result, the first quarter represents the company's most difficult comparison year-over-year. And despite this challenge, we were quite pleased with results.
We continue to see the resilience of our business and benefit from our operating model with a focus on local markets and a portfolio heavily concentrated in billboards.
2020 cost reduction initiatives implemented in response to COVID-19 continue to prove effective with consolidated operating expenses declining 9% in Q1. Adjusted EBITDA for the quarter was $152.4 million compared to $159.8 million in 2020, which was a decrease of 4.6%. On an acquisition-adjusted basis, the decline was 4.5%.
Adjusted EBITDA margin was 41.1%, expanding 180 basis points versus the first quarter of 2020. In addition to the cost reductions, lower interest expense contributed to AFFO growth and free cash flow also improved, increasing 10.6% in the quarter.
We experienced an acceleration of sales activity in both local and national markets within our portfolio. Relative to the first quarter of last year, local revenue growth outpaced national slightly, but against a difficult comparison for national, which grew in the low double digits in Q1 2020 over Q1 2019. Consistent with last year, local sales accounted for 79% of billboard revenue in the first quarter with national representing 21%.
Last year, in response to COVID-19, we demonstrated Lamar's operational flexibility, including our disciplined approach to CapEx. In 2021, we expect to return to a more regular year in terms of capital deployment. CapEx is anticipated to total approximately $150 million for the full year, including $55 million of maintenance CapEx.
During the first quarter, total CapEx was $16.3 million, with maintenance comprising $7.9 million. Q1 is seasonally low in CapEx spend and will accelerate in the coming quarters.
Given our strong financial position and the recovery in our business, we increased our appetite for acquisitions beginning in the fourth quarter of last year. While we are aggressively pursuing acquisitions, in the early stages of the year, there remained a valuation gap between buyers and sellers. Consequently, there was only modest investment activity in the first quarter.
Our acquisition pipeline has seen an uptick in potential opportunities over the last several weeks. We continue to anticipate that when all is said and done, 2021 will have been an active year.
Now turning to our balance sheet, which continues to be a critical focus for the company and core to our strategy and competitive advantage. We are quite pleased with the financial strength of Lamar coming through the COVID-19 pandemic. Our balance sheet is well positioned going forward and not only the strongest in the history of the company, but by far the strongest amongst our public company peers.
With our most recent bond issuance, during the first quarter, we have effectively refinanced the entire balance sheet since the beginning of 2020. This resulted in an interest expense reduction of $8.4 million in the first quarter relative to the first quarter of 2020.
Our debt maturity schedule is well-laddered and positioned to take advantage of the economic recovery post-COVID-19. After the AR securitization, which will mature in December and we intend to extend, our nearest term maturity is the revolving credit facility in 2025. Based on current debt outstanding, our weighted average interest rate is 3.3%, with a weighted average maturity of 7.3 years.
We ended the quarter with total leverage of 4x net debt-to-EBITDA as defined under our credit facility. As LTM EBITDA troughed in the first quarter, with the full year of COVID-impacted results now included, leverage should improve going forward. And we plan to finish the year below our 4x target. Our secured debt leverage was 0.9x at quarter end, and we expect our secured debt test to remain below 1x over the balance of the year. We are comfortably in compliance with both our total debt incurrence and secured debt maintenance tests against covenants of 7x and 4.5x, respectively.
At the end of the quarter, we had approximately $765 million of liquidity, comprised of $43 million of cash on hand, $11 million available on the securitization line and $711 million available under our revolver.
As Sean mentioned and included in this morning's release, we increased our AFFO guidance based on strong performance in the first quarter, which exceeded our expectations. The revised AFFO guidance of $5.40 to $5.60 per share represents an increase of $0.15 at the midpoint.
Looking at the balance of the year, we anticipate the second and third quarters to be the strongest on a comparable basis. Given the solid performance in Q4 2020, which included political and a presidential year, we expect Q4 2021 to have a more difficult comparison year-over-year.
Furthermore, because of our efforts around the balance sheet, cash interest in 2021 should be approximately $105 million or about $25 million lower than full year 2020. Taxes should come in slightly below our $10 million to $11 million historical level due to operations in the TRS, primarily our airport and transit division that are expected to be slower to recover.
Moving to our dividend policy. In the first quarter, we paid a cash dividend of $0.75 per share. Management's recommendation at the upcoming Board meeting will be to declare a cash dividend of $0.75 for the second quarter as well. This recommendation is subject to Board approval, and we will communicate the Board's decision in the ordinary course, following the Board of Directors' meeting later this month.
As Sean mentioned, we will evaluate our dividend for future quarters following Q2 results. Again, we are extremely pleased with this quarter's performance and are optimistic about the outlook for the remainder of the year. Our balance sheet remained strong, and we maintained excellent access to both the debt and equity capital markets.
A strong balance sheet is core to our operating strategy and serves as a significant competitive advantage. With our intense focus on the company's capital structure and increased flexibility despite the COVID-19 pandemic, Lamar is well positioned to take advantage of opportunities as they arise.
I will now turn the call back over to Sean.