Operator
Welcome to the iRhythm Technologies, Inc. Q1 2021 Earnings Conference Call. My name is Erin, and I'll be your operator for today's call. [Operator Instructions] Later, we will conduct a question-and-answer session. [Operator Instructions] Please note that this conference is being recorded. I'll now turn the call over to Leigh Salvo. Leigh, you may begin.
Leigh J. Salvo --
Managing Director
Thank you all for participating in today's call. Joining me are Mike Coyle, CEO; Doug Devine, CFO; and Dan Wilson, EVP, Strategy, Corporate Development and Investor Relations. Earlier today, iRhythm released financial results for the first quarter ended March 31, 2021. A copy of the press release is available on the company's website. Before we begin, I'd like to remind you that management will make statements during this call that include forward-looking statements within the meaning of federal securities laws, which are made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Any statements contained in this call that are not statements of historical fact should be deemed to be forward-looking statements. All forward-looking statements including, without limitation, those statements related to the impact of COVID-19 on our business, expectations for recovery, market opportunity, product performance, market expansion and penetration, productivity improvements, reimbursement, release of clinical data, operating trends and our future financial expectations including revenue, gross margins, profitability and operating expenses are based upon our current estimates and various assumptions. These statements involve material risks and uncertainties that could cause actual results or events to materially differ from those anticipated or implied by these forward-looking statements. Accordingly, you should not place undue reliance on these statements. In addition, we will refer to adjusted EBITDA, which is defined as EBITDA, excluding stock-based compensation expense. Adjusted EBITDA is a non-GAAP measure that is used to help investors understand iRhythm's ongoing business performance. For a list and description of the risks and uncertainties associated with our business, please refer to the Risk Factors section of our most recent annual and quarterly reports on Form 10-K and Form 10-Q, respectively, with the SEC. This conference call contains time-sensitive information and is accurate only as of the live broadcast today, May 6, 2021. iRhythm disclaims any intention or obligation, except as required by law, to update or revise any financial projections or forward-looking statements whether because of new information, future events or otherwise. And with that, I'll turn the call over to Mike.