POWER OF ATTORNEY





 The undersigned hereby constitutes and appoints Laurence Betterley, James

 Flaherty, Jeffrey Points, Michael Killeen, Alexander Rosenstein, Amanda

 Schmall and Lori Cobb, or any one of them acting alone, the undersigned's true

 and lawful attorney-in-fact and agent with full power of substitution and

 resubstitution, for the undersigned and in the undersigned's name, place and

 stead, in any and all capacities, to sign any or all Forms 3, 4 or 5 relating

 to beneficial ownership of securities of Cardiovascular Systems, Inc. (the

 "Issuer"), to file the same, with all exhibits thereto and other documents in

 connection therewith, with the Securities and Exchange Commission and to

 deliver a copy of the same to the Issuer, granting unto said attorney-in-fact

 and agent full power and authority to do and perform each and every act and

 thing requisite and necessary to be done in and about the premises, as fully

 to all intents and purposes as the undersigned might or could do in person,

 hereby ratifying and confirming all said attorney-in-fact and agent, or his

 substitute or substitutes, may lawfully do or cause to be done by virtue

 thereof.  The undersigned acknowledges that the foregoing attorney-in-fact, in

 serving in such capacity at the request of the undersigned, is not assuming

 any of the undersigned's responsibilities to comply with Section 16 of the

 Securities Exchange Act of 1934.





 This Power of Attorney shall remain in effect until such time as the

 undersigned is no longer subject to the provisions of Section 16 of the

 Securities Exchange Act of 1934 with respect to securities of the Issuer.





 The undersigned hereby indemnifies the attorneys-in-fact for all losses

 and costs the attorneys-in-fact may incur in connection with or arising from

 the attorneys-in-fact's execution of their authorities granted hereunder.





 IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to

 be executed as of this 13th day of November, 2013.









       /s/ David L. Martin

       David L. Martin