Exhibit 10.58

May 15, 2017
(revised per your request and emailed to your attorney’s office on June 28,
2017)

In Person and Via E-Mail

Personal and Confidential
Paul A. Koehn
295 Whitegate Lane
Wayzata, MN 55391

Re:    Separation Agreement and Release

Dear Paul:

As we discussed with you, your employment with Cardiovascular Systems, Inc.
(“CSI”) will end effective at the close of business on June 30, 2017 (the
“Separation Date”). The purpose of this Separation Agreement and Release letter
(“Agreement”) is to set forth the specific Salary and Wage Continuation Benefits
and other benefits CSI will provide to you in keeping with the CSI Executive
Officer Severance Plan dated July 26, 2016 (the “Severance Plan”) in exchange
for your agreement to the terms and conditions of this Agreement. Please note
that you may not execute this Agreement until your Separation Date.
 
By your signature below, you agree to the following terms and conditions:

1.    End of Employment.    Your employment with CSI will end effective at the
close of business on the Separation Date. By signing below, you agree that as of
the Separation Date you will be deemed to have also automatically resigned from
all positions with CSI, if and as applicable. Except as set forth herein for
Salary and Wage Continuation Benefits in Section 2.a. and bonus pay in Section
2.b., upon your receipt of your final paycheck for services through the
Separation Date, you will have received all wages, bonuses, commissions and
compensation owed to you by virtue of your employment with CSI or termination
thereof. With your final paycheck, you will also receive payment from CSI for
240 hours of accrued but unused Paid Time Off (PTO) at your regular rate per CSI
policy. If applicable, information regarding your right to elect COBRA coverage
will be sent to you via separate letter. If elected, your COBRA period will
begin July 1, 2017.
        
You are not eligible for any other payments or benefits by virtue of your
employment with CSI or termination thereof except for those expressly described
in this Agreement. You will not receive the pay and benefits described in
Section 2 of this Agreement if you (i) do not sign this Agreement and return it
to CSI by the Offer Expiration, (ii) rescind this Agreement after signing it, or
(iii) violate any of the terms and conditions set forth in this Agreement,
Sections 9 - 13 of your Employment Agreement with CSI dated February 28, 2007
(the “Employment Agreement”), the Severance Plan, or any other written agreement
in effect between you and CSI containing post-

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employment obligations. In addition, the pay and benefits described in Section 2
of this Agreement shall be subject to reduction, cancellation, forfeiture,
offset or recoupment as and to the extent required by the applicable provisions
of any law (including without limitation Section 10D of the Securities Exchange
Act of 1934, as amended, and the rules and regulations promulgated thereunder),
government regulation or stock exchange listing requirement, or clawback policy
or provision implemented by CSI pursuant to such law, regulation or listing
requirement.

2.    Salary and Wage Continuation Benefits. Specifically in consideration of
your signing this Agreement and subject to the limitations, obligations, and
other provisions contained in this Agreement, CSI agrees to the following as set
forth in and subject to the Severance Plan:

a.    To pay you fifteen (15) months of Salary and Wage Continuation Benefits
based on your ending Base Salary, in the gross amount of $418,108.59, less
applicable deductions and withholding, to be paid to you in substantially equal
installments with the first such payment to be made to you on the sixtieth
(60th) day following your Separation Date, provided the rescission periods
described in Section 5 have expired without rescission, and continuing
thereafter on CSI’s regular payday schedule. The first payment will include
“catch-up” pay for the period between your Separation Date and the first payment
date.

b.    To continue your bonus eligibility under the Fiscal Year 2017 bonus plan
in which you participated for your period of employment during such bonus period
(July 1, 2016 through June 30, 2017 = 12/12ths – the full year). Bonuses under
such plan will be calculated following the close of Fiscal Year 2017 and, if any
bonus is owing to you thereunder, such bonus will be paid to you no earlier than
January 1, 2018 and no later than January 15, 2018.

c.    To provide you with a six-month outplacement services package through
Pathfinder free of charge as more fully set forth in an attachment hereto. Your
use of such services must commence no later than July 1, 2017 and end no later
than December 31, 2017.

d.    Provided you are eligible for and timely elect COBRA coverage, CSI shall
pay up to $1,738.89/month toward your COBRA premiums necessary to continue your
health, dental and/or life insurance coverage in effect for yourself and your
eligible dependents as of the Separation Date until the earliest of (A)
September 30, 2018, (B) the expiration of your eligibility for the continuation
coverage under COBRA, or (C) the date on which you participate in another health
insurance plan (such period from the termination date through the earliest of
(A) through (C), the “COBRA Payment Period”). You shall timely pay your share of
the COBRA premiums. Notwithstanding the foregoing, if CSI determines, in its
sole discretion, that its payment of the COBRA premiums would result in a
violation of the nondiscrimination rules of Section 105(h)(2) of the Code or any
statute or regulation of similar effect (including but not limited to the 2010
Patient Protection and Affordable Care Act, as amended by the 2010 Health Care
and Education Reconciliation Act), then in lieu of providing the COBRA premiums,
CSI, in its sole discretion, may elect to instead pay you on the first day of
each month of the COBRA Payment Period, a fully taxable cash payment equal to
the COBRA premiums for that month, subject to applicable tax withholdings (such
amount, the “Special Severance Payment”), for the remainder of the COBRA Payment
Period. You may, but are not obligated to, use such Special Severance Payment
toward

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the cost of COBRA premiums. If you participate in another health plan or
otherwise cease to be eligible for COBRA during the period provided in this
clause, you must immediately notify CSI of such event, and all payments and
obligations under this clause shall cease.

e.    To accelerate the vesting of 6,867 of your time-vested shares of
restricted stock that were previously granted to you that would have vested
within the 12 month period following the Separation Date had you remained
employed by CSI during such period such that they are deemed fully vested as of
the expiration of the rescission periods described in Section 5 below without
rescission by you.

f.    To provide for the vesting of up to 7,960 of your performance-based shares
of restricted stock that were previously granted to you that may vest in
accordance with the Restricted Stock Agreement – Performance-Based Vesting
relating to such shares following the Separation Date; provided, that the
performance criteria for such vesting are met as determined by CSI in accordance
with the terms for such shares of restricted stock (in or around August or
September 2019) such that, if and to the extent applicable, such shares will
vest as of such determination.

g.    Permit any of your outstanding stock options as of the Separation Date to
remain exercisable through the respective award expiration dates.

h.    In the event of your death prior to the end of Salary and Wage
Continuation Benefits, COBRA health benefits and any other benefit provided to
you under this Agreement, your beneficiary or beneficiaries, as you designate in
writing to the Company or, in the absence of such designation, to the surviving
spouse, or if there is no surviving spouse, then the executor, administrator or
other personal representative of your Estate will be entitled to receive (i) any
unpaid Salary and Wage Continuation Benefits as set forth in Section 2(a) above;
(ii) any unpaid bonus or other payments as set forth in Section 2(b) above; and
(iii) all other payments, benefits or fringe benefits to which you shall be
entitled under the terms of this Agreement, as set forth in Sections 1 and
2(d)-(h) above, to the full extent permitted by law.

3.    Release of Claims. Specifically in consideration of the pay and benefits
described in Section 2, to which you would not otherwise be entitled, by signing
this Agreement you, for yourself and anyone who has or obtains legal rights or
claims through you, agree to the following:

a.    You hereby do release and forever discharge the “Released Parties” (as
defined in Section 3.e. below) of and from any and all manner of claims,
demands, actions, causes of action, administrative claims, liability, damages,
claims for punitive or liquidated damages, claims for attorney’s fees, costs and
disbursements, individual or class action claims, or demands of any kind
whatsoever, you have or might have against them or any of them, whether known or
unknown, in law or equity, contract or tort, arising out of or in connection
with your employment with CSI, or the termination of that employment, or
otherwise, and however originating or existing, from the beginning of time
through the date of your signing this Agreement.

b.    This release includes, without limiting the generality of the foregoing,
any claims you may have for, wages, bonuses, commissions, penalties, deferred
compensation, vacation,

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sick, and/or PTO pay, separation pay and/or benefits, including, without
limitation, arising under the Severance Plan; tortious conduct, defamation,
invasion of privacy, negligence, emotional distress; breach of implied or
express contract (including, without limitation, arising under your Employment
Agreement), estoppel; wrongful discharge (based on contract, common law, or
statute, including any federal, state or local statute or ordinance prohibiting
discrimination or retaliation in employment); violation of any of the following:
the United States Constitution, the Minnesota Constitution, the Minnesota Human
Rights Act, Minn. Stat. § 363A.01 et seq., Minn. Stat. § 181.932, Title VII of
the Civil Rights Act, 42 U.S.C. § 2000e et seq., the Age Discrimination in
Employment Act, 29 U.S.C. § 621 et seq., the Americans with Disabilities Act, 42
U.S.C. § 12101 et seq., the Employee Retirement Income Security Act of 1974, 29
U.S.C. § 1001 et seq., the Family and Medical Leave Act, 29 U.S.C. § 2601 et
seq., the National Labor Relations Act, 29 U.S.C. § 151 et seq., the
Sarbanes-Oxley Act, 15 U.S.C. § 7201 et seq.; any paid sick time law; any claim
for retaliation under federal, state or local law; all waivable claims arising
under Minnesota statutes; and any claim for discrimination, harassment or
retaliation based legally-protected class status under federal, state or local
law. You understand and agree that, by signing this Agreement, you waive and
release any claim to employment with CSI.

c.    If you file, or have filed on your behalf, a charge, complaint, or action,
you agree that the separation pay and benefits described above in Section 2 are
in complete satisfaction of any and all claims in connection with such charge,
complaint, or action and you waive, and agree not to take, any award of money or
other damages from such charge, complaint, or action. Notwithstanding the
foregoing, you do not waive your right to receive and fully retain a monetary
award from a government-administered whistleblower award program, such as that
administered by the Securities and Exchange Commission (“SEC”), for providing
information directly to a governmental agency.

d.    You are not, by signing this Agreement, releasing or waiving (1) any
vested interest you may have in any 401(k) or profit sharing plan by virtue of
your employment with CSI, (2) any rights or claims that may arise after the
Agreement is signed, (3) the right to institute legal action for the purpose of
enforcing the provisions of this Agreement, (4) any rights you have to workers’
compensation benefits, (5) any rights you have under state unemployment
compensation benefits laws, (6) the right to file a charge or complaint with a
governmental agency such as the Equal Employment Opportunity Commission
(“EEOC”), the National Labor Relations Board (“NLRB”), the Occupational Safety
and Health Administration (“OSHA”), the SEC or any other federal, state or local
governmental agency, subject to Section 3(c) above, (7) the right to communicate
with, testify, assist, or participate in an investigation, hearing, or
proceeding conducted by, the EEOC, NLRB, OSHA, SEC or other governmental agency,
(8) any rights you have under the Consolidated Omnibus Budget Reconciliation Act
(“COBRA”), (9) your rights with regard to your stock options with CSI, if any,
which shall be governed by those applicable operative agreement(s), as modified
by Section 2 above, (10) any claims arising under the Indemnification Agreement
between you and CSI dated February 25, 2009 (the “Indemnification Agreement”) or
(11) the right to coverage and indemnification under CSI’s directors’ and
officers’ insurance coverage as set forth in CSI’s D&O insurance policy and/or
applicable law. Further, nothing in this Agreement prohibits you from reporting
possible violations of law or regulation to any governmental agency or
regulatory

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authority, including but not limited to the SEC, or from making other
disclosures that are protected under the whistleblower provisions of applicable
law or regulation.

    e.    The “Released Parties,” as used in this Agreement, shall mean
Cardiovascular Systems, Inc. and any parent, subsidiaries, divisions, affiliated
entities, insurers, and its and their present and former officers, directors,
shareholders, trustees, employees, agents, attorneys, representatives and
consultants, and the successors and assigns of each, whether in their individual
or official capacities, and the current and former trustees or administrators of
any pension or other benefit plan applicable to the employees or former
employees of CSI, in their official and individual capacities.

4.    Notice of Right to Consult Attorney and Twenty-One (21) Calendar Day
Consideration Period. By signing this Agreement, you acknowledge and agree that
CSI has informed you by this Agreement that (1) you have the right to consult
with an attorney of your choice prior to signing this Agreement, and (2) you are
entitled to at least Twenty-One (21) calendar days from your receipt of this
Agreement to consider whether the terms are acceptable to you.

5.    Notification of Rights under the Minnesota Human Rights Act (Minn. Stat.
Chapter 363A) and the Federal Age Discrimination in Employment Act (29 U.S.C. §
621 et seq.). You are hereby notified of your right to rescind the release of
claims contained in Section 3 with regard to claims arising under the Minnesota
Human Rights Act, Minnesota Statutes Chapter 363A, within fifteen (15) calendar
days of your signing this Agreement, and with regard to your rights arising
under the federal Age Discrimination in Employment Act, 29 U.S.C. § 621 et seq.,
within seven (7) calendar days of your signing this Agreement. The two
rescission periods shall run concurrently. In order to be effective, the
rescission must (a) be in writing; (b) delivered to Laura Gillund, Vice
President of Human Resources & Professional Development, 1225 Old Highway 8 NW,
St. Paul, MN 55112, by hand or mail within the required period; and (c) if
delivered by mail, the rescission must be postmarked within the required period,
properly addressed to Laura Gillund as set forth above, and sent by certified
mail, return receipt requested. You understand and agree that if you rescind any
part of this Agreement in accordance with this Section 5, CSI will have no
obligation to provide you the payments and benefits described in Section 2 of
this Agreement and you will be obligated to return to CSI any payment(s) and
benefits already received in connection with Section 2 of this Agreement.

6.    Return of Property. You acknowledge and agree that all documents and
materials relating to the business of, or the services provided by, CSI are the
sole property of CSI. You agree and represent that you have returned to CSI all
of its property, including but not limited to, all medical device and other
equipment, customer records and other documents and materials, whether on
computer disc, hard drive or other form, and all copies thereof, within your
possession or control, which in any manner relate to the business of, or the
duties and services you performed on behalf of CSI.

7.    Ongoing Obligations Under Your Employment Agreement. You are hereby
reminded of your ongoing obligations to CSI under Paragraphs 9 - 13 of your
Employment Agreement with CSI. Nothing in this Agreement or elsewhere is
intended to or will be used in any

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way to prevent disclosure of confidential information in accordance with the
immunity provisions set forth in Section 7 of the Defend Trade Secrets Act of
2016 (18 U.S.C. § 1833(b)), meaning disclosure (i) in confidence to a government
official or attorney solely for the purpose of reporting or investigating a
suspected legal violation; or (ii) under seal in connection with a lawsuit
(including an anti-retaliation lawsuit).

8.    Cooperation. You agree that through September 30, 2018 or as long as you
continue to receive Salary and Wage Continuation payments under this Agreement,
whichever occurs first, you will respond in a timely and helpful manner via
telephone or email to CSI’s questions regarding your employment with CSI, such
as, but not limited to, status of projects, customer matters, location of data,
passwords, etc.

9.    Non-Disparagement and Confidentiality. You promise and agree not to
disparage CSI, its directors, officers, shareholders, employees, products or
services, and CSI agrees to instruct its Executive level employees and its Board
of Directors as of June 30, 2017 not to disparage you, either orally or in
writing. You further promise and agree not to disclose or discuss, directly or
indirectly, in any manner whatsoever, any information regarding either (1) the
contents and terms of this Agreement, or (2) the substance and/or nature of any
dispute between CSI and any employee or former employee, including yourself.
Notwithstanding the foregoing, nothing in this Section 9 or this Agreement shall
prohibit or limit you from discussing or disclosing this confidential
information with or to your legal and financial advisors and your spouse, if
applicable, provided they agree to keep the information confidential, or from
freely and truthfully communicating with, with or without notice to CSI, federal
and state tax authorities, the state unemployment compensation department, other
government agencies, or as otherwise required or allowed by law. You acknowledge
and agree that CSI has obligations to describe the contents and terms of this
Agreement and file this Agreement pursuant to the rules and regulations of the
SEC (as defined above).

10.    Code Section 409A. It is intended that any amounts payable under the
Agreement shall be exempt from or comply with the applicable requirements, if
any, of Section 409A of the Internal Revenue Code of 1986, as amended, and the
notices, regulations and other guidance of general applicability issued
thereunder (“Code Section 409A”), and the parties will interpret the Agreement
in a manner that will preclude the imposition of additional taxes and interest
imposed under Code Section 409A. Any payments under this Agreement that may be
excluded from Code Section 409A either as separation pay due to an involuntary
separation from service or as a short-term deferral will be so excluded to the
maximum extent possible. This Agreement may be amended (as mutually determined
by the parties) to the extent necessary to comply with Code Section 409A.

11.    Remedies. If either party breaches any term of this Agreement, if you
breach any of the specific paragraphs of your Employment Agreement referenced in
this Agreement, or if either party breaches any other written agreement in
effect between you and CSI, the prevailing party in any enforcement action as
determined by a court of competent jurisdiction shall be entitled to its
available legal and equitable remedies, including but not limited payment by the
non-prevailing party of the prevailing party’s attorneys’ fees and costs
incurred in connection with such action. If CSI seeks and/or obtains relief from
an alleged breach of this Agreement, all of the provisions of this Agreement
shall remain in full force and effect.

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12.    Non-Admission. It is expressly understood that this Agreement does not
constitute, nor shall it be construed as, an admission by CSI or you of any
liability or unlawful conduct whatsoever. CSI and you specifically deny any
liability or unlawful conduct. Additionally, by signing this Agreement you
acknowledge and agree that you are not aware, to the best of your knowledge, of
any conduct, on your part or on the part of another employee at CSI, that
violated CSI’s code of conduct, applicable policies and procedures, or
applicable law or otherwise exposed CSI to any liability, whether criminal or
civil, and whether to any government, individual or other entity.  Further, you
acknowledge and agree that you are not aware of any material violations by CSI
and/or any of the Released Parties or employees of CSI of any statute,
regulation or other rules that have not been addressed by CSI through
appropriate compliance and/or corrective action.

13.    Successors and Assigns. This Agreement is personal to you and may not be
assigned by you without the written agreement of CSI. The rights and obligations
of this Agreement shall inure to the successors and assigns of CSI.

14.    Enforceability. If a court finds any term of this Agreement to be
invalid, unenforceable, or void, the parties agree that the court shall modify
such term to make it enforceable to the maximum extent possible. If the term
cannot be modified, the parties agree that the term shall be severed and all
other terms of this Agreement shall remain in effect.

15.    Law, Jurisdiction and Venue, Jury Trial Waiver. This Agreement will be
construed and interpreted in accordance with, and any dispute or controversy
arising from any breach or asserted breach of this Agreement will be governed
by, the laws of the State of Minnesota, without regard to any choice of law
rules. Any action brought to enforce or interpret this Agreement must be brought
in the state or federal courts for the State of Minnesota sitting in Hennepin
County, Minnesota, and the parties hereby consent to the jurisdiction and venue
of such courts in the event of any dispute. Each of the parties knowingly and
voluntarily waives all right to trial by jury in any action or proceeding
arising out of or relating to this Agreement or for recognition or enforcement
of any judgment.

16.    Full Agreement. This Agreement contains the full agreement between you
and CSI and may not be modified, altered, or changed in any way except by
written agreement signed by both parties. The parties agree that this Agreement
supersedes and terminates any and all other written and oral agreements and
understandings between the parties, except for any applicable stock option
agreements, however, Sections 2(e), 2(f), and 2(g) of this Agreement shall
supersede any conflicting language in the stock option agreements; Sections 8
-14 of your Employment Agreement; the Indemnification Agreement; the Severance
Plan, and any other written agreement in effect between you and CSI containing
post-employment obligations, which shall continue in full force and effect
according to their terms and shall survive the termination of your employment.

17.    Counterparts.     This Agreement may be executed by facsimile or
electronic transmission and in counterparts, each of which shall be deemed an
original and all of which shall constitute one instrument.

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18.    Acknowledgment of Reading and Understanding. By signing this Agreement,
you acknowledge that you have read this Agreement, including the release of
claims contained in Section 3, and understand that the release of claims is a
full and final release of all claims you may have against CSI and the other
entities and individuals covered by the release. By signing, you also
acknowledge and agree that you have entered into this Agreement knowingly and
voluntarily, and that CSI has informed you that you have the right to consult
with an attorney of your choice prior to signing this Agreement.

The deadline for accepting this Agreement is 5:00 p.m. on July 3, 2017, which
you acknowledge and agree is more than 21 calendar days following your receipt
of this Agreement (the “Offer Expiration”), provided you may not sign this
Agreement until June 30, 2017. If not accepted by the Offer Expiration, the
offer contained herein will expire. After you have reviewed this Agreement and
obtained whatever advice and counsel you consider appropriate regarding it,
please evidence your agreement to the provisions set forth in this Agreement by
dating and signing the Agreement between June 30, 2017 and July 3, 2017. Please
then return a signed Agreement to me no later than the Offer Expiration. Please
keep a copy for your records.

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Paul, on behalf of CSI, we thank you for your service and wish you all the best.

Sincerely,

/s/ Laura Gillund

Laura Gillund
Chief Talent Officer

ACKNOWLEDGMENT AND SIGNATURE

By signing below, I, Paul A. Koehn, acknowledge and agree to the following:

•
I have read this Separation Agreement and Release carefully.

•
I understand and agree to all of the terms of the Separation Agreement and
Release.

•
I am knowingly and voluntarily releasing my claims against CSI and the other
persons and entities defined as the Released Parties.

•
I have not, in signing this Agreement, relied upon any statements or
explanations made by CSI except as for those specifically set forth in this
Separation Agreement and Release.

•
I intend this Separation Agreement and Release to be legally binding.

•
I am signing this Separation Agreement and Release on or after my last day of
employment with CSI.

Accepted this _30th_ day of _____June_____, 2017.

____/s/ Paul A. Koehn____________________
Paul A. Koehn