POWER OF ATTORNEY





 The undersigned hereby constitutes and appoints 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/ Laurence L. Betterley

       Laurence L. Betterley