Our financial instruments include cash and cash equivalents, accounts receivable, marketable securities, accounts payable, interest rate swap agreement and contingent earn outs. The carrying amount of cash and cash equivalents, accounts receivable, and accounts payable approximates fair value due to the immediate or short-term maturities. The marketable securities and interest rate swap agreement has been recorded at its fair value based on a valuation received from an independent third party. The contingent earn out has been recorded at fair value using the income approach.

Fair value is the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. This policy establishes a fair value hierarchy which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The policy describes three levels of inputs that may be used to measure fair value which are provided in the table below.



Level 1	Quoted prices in active markets for identical assets or liabilities. Level 1 assets include money market funds that are traded in an active exchange market.



Level 2	Observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. When quoted market prices are unobservable, we obtain pricing information from an independent pricing vendor. The pricing vendor uses various pricing models for each asset class that are consistent with what other market participants would use. The inputs and assumptions to the model of the pricing vendor are derived from market observable sources including: benchmark yields, reported trades, broker/dealer quotes, issuer spreads, benchmark securities, bids, offers, and other market-related data. The pricing vendor considers all available market observable inputs in determining the evaluation for a security. Thus, certain securities may not be priced using quoted prices, but rather determined from market observable information. Included in Level 2 assets is our interest rate swap agreement which is valued using a mid-market valuation model.



Level 3	Unobservable inputs that are supported by little or no market activity and are significant to the fair value of the assets or liabilities. Level 3 assets and liabilities include financial instruments whose value is determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant management judgment or estimation. This category includes the auction rate securities where independent pricing information was not able to be obtained and the contingent consideration related to the acquisitions of Vortex, Microsulis and Clinical Devices. Our investments in auction-rate securities were classified as Level 3 as quoted prices were unavailable since these auction rate securities issued by New York state and local government authorities failed auction. Due to limited market information, we utilized a discounted cash flow (“DCF”) model to derive an estimate of fair value for contingent considerations for all periods presented. The assumptions used in preparing the DCF model included estimates with respect to the discount rate, amount and timing of future interest and principal payments and forward projections. Assumptions associated with the auction rate securities include the interest rate benchmarks, the probability of full repayment of the principal considering the credit quality and guarantees in place, and the rate of return required by investors to own such securities given the current liquidity risk.

The following tables provide information by level for assets and liabilities that are measured at fair value (in thousands):



	Fair Value Measurements using inputs considered as:
	Level 1		Level 2		Level 3		Fair Value at May 31, 2016
Financial Assets
Marketable securities
New York State government agency obligations	$	—	$	—	$	1,653	$	1,653
Total	—		—		1,653		1,653
Total Financial Assets	$	—	$	—	$	1,653	$	1,653
Financial Liabilities
Contingent liability for acquisition earn out	—		—		38,275		38,275
Total Financial Liabilities	$	—	$	—	$	38,275	$	38,275



	Fair Value Measurements using inputs considered as:
	Level 1		Level 2		Level 3		Fair Value at May 31, 2015
Financial Assets
Marketable securities
New York State government agency obligations	$	—	$	—	$	1,689	$	1,689
Total	—		—		1,689		1,689
Total Financial Assets	$	—	$	—	$	1,689	$	1,689
Financial Liabilities
Interest rate swap agreements	$	—	$	257	$	—	$	257
Contingent liability for acquisition earn out	—		—		47,384		47,384
Total Financial Liabilities	$	—	$	257	$	47,384	$	47,641

There were no transfers in and out of Level 1, 2 and 3 measurements for the years ended May 31, 2016 and 2015.

The components of Level 3 fair value instruments as of May 31, 2016 are shown below (in thousands):



	Financial Assets			Financial Liabilities
	Fair Value Measurements Using Significant Unobservable Inputs (Level 3)			Fair Value Measurements Using Significant Unobservable Inputs
Balance at May 31, 2015	$	1,689		$	47,384
Change in fair value of contingent consideration (1)	—			948
Currency (gain) loss from remeasurement	—			43
Fair market value adjustments	(36		)	—
Contingent consideration payments	—			(10,100		)
Balance at May 31, 2016	$	1,653		$	38,275

The components of Level 3 fair value instruments as of May 31, 2015 are shown below (in thousands):



	Financial Assets			Financial Liabilities
	Fair Value Measurements Using Significant Unobservable Inputs (Level 3)			Fair Value Measurements Using Significant Unobservable Inputs
Balance at May 31, 2014	$	1,809		$	67,331
Change in fair value of contingent consideration (1)	—			(8,196		)
Currency (gain) loss from remeasurement	—			(529		)
Included in other comprehensive income (loss)	(120		)	—
Contingent consideration payments	—			(11,222		)
Balance at May 31, 2015	$	1,689		$	47,384

(1) Change in the fair value of contingent consideration is included in earnings and comprised of changes in estimated earn out payments based on projections of company performance and amortization of the present value discount.

Contingent Liability for Acquisition Earn Outs

Certain of our business combinations involve the potential for the payment of future contingent consideration upon the achievement of certain product development milestones and/or various other favorable operating conditions. Payment of the additional consideration is generally contingent on the acquired company reaching certain performance milestones, including attaining specified revenue levels or achieving product development targets. Contingent consideration is recorded at the estimated fair value of the contingent milestone payments on the acquisition date. The fair value of the contingent milestone consideration is remeasured at the estimated fair value at each reporting period with the change in fair value recognized as income or expense within change in fair value of contingent consideration in the consolidated statement of operations. We measure the initial liability and remeasure the liability on a recurring basis using Level 3 inputs as defined under authoritative guidance for fair value measurements.

Contingent consideration liabilities will be remeasured to fair value each reporting period using projected net sales, discount rates, probabilities of payment and projected payment dates. Projected contingent payment amounts are discounted back to the current period using a discounted cash flow model. Projected net sales are based on our internal projections and extensive analysis of the target market and the sales potential. Increases in projected net sales and probabilities of payment may result in higher fair value measurements in the future. Increases in discount rates and the projected time to payment may result in lower fair value measurements in the future. Increases or decreases in any valuation inputs in isolation may result in a significantly lower or higher fair value measurement in the future.

The recurring Level 3 fair value measurements of the contingent consideration liabilities include the following significant unobservable inputs as of May 31, 2016 (in thousands of dollars):



	Fair value at May 31, 2016		Valuation Technique	Unobservable Input	Range
Revenue based payments	$	35,325	Discounted cash flow	Discount rate Probability of payment Projected fiscal year of payment	4% 75% - 100% 2017 - 2022
Milestone based payments	2,950		Discounted cash flow	Discount rate Probability of payment Projected fiscal year of payment	16% 75% - 100% 2017
	$	38,275

At May 31, 2016, the estimated potential amount of undiscounted future contingent consideration that we expect to pay as a result of all completed acquisitions is approximately $40.8 million. The milestones associated with the contingent consideration must be reached in future periods ranging from fiscal years 2017 to 2022 in order for the consideration to be paid.