On January 26, 2017, National Instruments Corporation (“NI”)
furnished financial information to Item 2.02 of Form 8-K (the
“Form 8-K”) regarding financial results for NI’s fourth fiscal
quarter ended December 31, 2016. Based on NI’s additional
analysis of its calculation for provision for income taxes for
the three and twelve-month periods ended December 31, 2016, NI is
furnishing in the tables below revisions to certain of the
financial information included in its Form 8-K.

The additional analysis referred to above did not impact NI’s
financial guidance included in the Form 8-K and NI is confirming,
as of the date hereof, its financial guidance previously
furnished in the Form 8-K dated January 26, 2017.

The information herein shall not be deemed “filed” for purposes
of Section 18 of the Securities Exchange Act of 1934, as amended
(the “Exchange Act”), or otherwise subject to the liabilities
of that section, nor shall it be deemed incorporated by reference
in any filing under the Securities Act of 1933, as amended, or
the Exchange Act.

NI’s audited financial results for the year ended December 31,
2016 will be contained in its Annual Report on Form 10-K which is
expected to be filed with the Securities and Exchange Commission
on or about the date hereof.

A reconciliation of the financial information previously
furnished in the Form 8-K on January 26, 2017 to the revised
financial information is detailed in the tables below;

Non-GAAP Presentation

In addition to disclosing results determined in accordance with
GAAP, NI discloses certain non-GAAP operating results and
non-GAAP information that exclude certain charges. In this
Current Report on Form 8-K, NI has presented its provision for
income taxes, net income and basic and fully diluted EPS for the
three- and twelve-month periods ending Dec. 31, 2016 on a GAAP
and non-GAAP basis.

When presenting non-GAAP information, NI includes a
reconciliation of the non-GAAP results to the GAAP results. NI
believes that including the non-GAAP results assists investors in
assessing the company’s operational performance and its
performance relative to its competitors. NI presents these
non-GAAP results as a complement to results provided in
accordance with GAAP, and these results should not be regarded as
a substitute for GAAP. NI uses these non-GAAP measures to manage
and assess the profitability and performance of its business and
does not consider stock-based compensation expense, amortization
of acquisition-related intangibles, acquisition-related
transaction costs, taxes levied on the transfer of acquired
intellectual property, foreign exchange loss on acquisitions,
acquisition-related fair value adjustments, and restructuring
charges in managing its operations. Specifically, NI uses
non-GAAP measures to plan and forecast future periods; to
establish operational goals; to compare with its business plan
and individual operating budgets; to measure management
performance for the purposes of executive compensation, including
payments to be made under bonus plans; to assist the public in
measuring the company’s performance relative to the company’s
long-term public performance goals; to allocate resources; and,
relative to the company’s historical financial performance, to
enable comparability between periods. NI also considers such
non-GAAP results to be an important supplemental measure of its
performance.

This Current Report on Form 8-K discloses NI’s EBITDA for the
three- and twelve- month periods ending Dec. 31, 2016. NI
believes that including the EBITDA results assists investors in
assessing the company’s operational performance relative to its
competitors. A reconciliation of EBITDA to GAAP net income is
included with this Current Report on Form 8-K.

Forward-Looking Statements

The foregoing statement whereby NI is confirming, as of the date
hereof, its financial guidance previously furnished in the Form
8-K dated January 26, 2017 is a “forward-looking statement”
that is subject to a number of risks and uncertainties, including
the risk of adverse changes or fluctuations in the global
economy, foreign exchange fluctuations, fluctuations in demand
for NI’s products including orders from its largest customer,
component shortages, delays in the release of new products, NI’s
ability to effectively manage its operating expenses,
manufacturing inefficiencies and the level of capacity
utilization, the impact of any recent or future acquisitions,
expense overruns, adverse effects of price changes or effective
tax rates. Actual results may differ materially from the expected
results. NI directs readers to its Form 10-K for the year ended
Dec. 31, 2015, its Form 10-Q for the quarter ended Sept. 30,
2016; and the other documents it files with the SEC for other
risks associated with the company’s future performance.