Since last quarter, we completed the last of our divestitures, retiring our debt and stockpiling over $500 million of cash on the balance sheet.
And by 2005, we were working with surgeons to design and manufacture customized patient-specific surgical guides and instruments using 3D printing.
Of note, our Healthcare business grew over 28% in our most recent quarter and over 44% on an organic basis, which is where we disregard the businesses that we have divested.
Our solid execution in the face of these challenges in the third quarter resulted in strong double-digit growth with revenues increasing by 15% before adjusting for divestitures.
When these adjustments are made, which is a much better reflection of our core business performance, revenues were up over 36% versus 2020 and up over 20% versus our pre-pandemic 2019 third quarter, a benchmark we consider very important.
As Jagtar will discuss shortly, in addition to the strong revenue performance, our EBITDA climbed by over 125%.
For the third quarter, we reported revenue of $156.1 million, an increase of 14.6% compared to the third quarter of 2020.
Our organic revenue growth, which excludes divestitures completed in 2020 and 2021, was 35.9% in Q3 2021 versus Q3 2020.
Our revenue in the third quarter 2021 was 21.2% higher than pre-pandemic Q3 2019.
We reported GAAP net income of $2.34 per share in the third quarter of 2021 compared to a GAAP loss of $0.61 in the third quarter of 2020.
For our non-GAAP results, we reported non-GAAP income of $0.08 per share in the third quarter of 2021 compared to a non-GAAP loss of $0.03 per share in the third quarter of 2020.
Healthcare grew 28.3% year-over-year and decreased 7.8% compared to the last quarter.
Adjusted for divestitures, Healthcare revenue increased 44.5% year-over-year as a result of strong demand for dental applications in both printers and materials.
Our Industrial segment generated revenue growth of 4% to $79.7 million compared to the same period last year and was flat to last quarter, reflecting the divestiture of the on-demand manufacturing parts business during the quarter.
Adjusted for divestitures, Industrial revenue increased 28.1% year-over-year and 2.1% over the last quarter.
We reported gross profit margin of 41.2% in the third quarter of 2021 compared to 43.1% in the third quarter of 2020.
Non-GAAP gross profit margin was 41.5% compared to 43.2% in the same period last year.
If we exclude the impact of those divestitures, gross profit -- gross margins increased 80 basis points in the third quarter of 2021 compared to the same period last year, driven by 2020 cost actions and the higher revenue, which resulted in better capacity utilization.
Year-to-date, our non-GAAP gross profit margin was 42.6% and we expect full year gross profit margins to be between 41% and 43%.
Operating expenses for the quarter were $81.5 million on a GAAP basis, a decrease of 35.4% compared to the third quarter of 2020.
Our non-GAAP operating expenses in the third quarter were $54.1 million, a decrease -- an 8% decrease from the third quarter of the prior year.
Compared to the second quarter of 2021, non-GAAP operating expenses decreased 2%, primarily driven by lower R&D spend.
Adjusted EBITDA, defined as non-GAAP operating profit plus depreciation, was $16.3 million or 10.5% of revenue compared to $7.2 million or 5.3% of revenue in the third quarter 2020.
We are pleased to show $502.8 million of cash on the balance sheet, an increase of $418.4 million since the beginning of the year.
During the quarter, we generated $20.7 million of cash from operations, marking the fourth straight quarter of positive cash from operations.
Now that we have demonstrated consistent profitability and cash generation and post-divestiture $0.5 billion of cash on hand, we are in a prime position to continue growing the company by taking a disciplined approach to invest organic and inorganic solutions that will solve customers' complex needs, drive adoption of additive manufacturing and generate high margin recurring revenue streams.
The cash considerations for these will total approximately $130 million, leaving roughly $370 million of cash.
We had just announced results for the second quarter of 2020 that included negative operating cash flow of $21 million for the first half of that year, cash and cash equivalents on the balance sheet of only $64 million and $22 million of debt.
We have generated over $60 million of operating cash this year for the third quarter and ended the quarter with over $500 million of cash and cash equivalents with no debt.
We are 100% focused on additive manufacturing and growing strongly in our core markets.

Summary:
For the third quarter, we reported revenue of $156.1 million, an increase of 14.6% compared to the third quarter of 2020.
We reported GAAP net income of $2.34 per share in the third quarter of 2021 compared to a GAAP loss of $0.61 in the third quarter of 2020.
For our non-GAAP results, we reported non-GAAP income of $0.08 per share in the third quarter of 2021 compared to a non-GAAP loss of $0.03 per share in the third quarter of 2020.
Year-to-date, our non-GAAP gross profit margin was 42.6% and we expect full year gross profit margins to be between 41% and 43%.