**Exhibit 10.20(b)**

**AMENDMENTTOMANAGEMENT CHANGE IN CONTROL AGREEMENT**

**THISAMENDMENT** is dated the 17th day of April,2007, by and between **EVOLVING SYSTEMS, INC.**(“Company”)and **BRIAN R. ERVINE**  (“Executive”).

WHEREAS, the Boardof Directors of the Company has approved an amendment to the Management Changein Control Agreement (“Agreement”) to increase the amount of severancecompensation and to modify the definition of the “Severance Period” and “SeveranceCompensation” as described in Section 4 of the Agreement.

NOW, THEREFORE, inconsideration of the mutual terms and conditions described herein, the partiesagree as follows:

(1)                                   Section4 of the Agreement is deleted, the following provision inserted in its placeand stead:

**COMPENSATION PAYABLE UPONQUALIFIED TERMINATION.**  Uponthe occurrence of a Qualified Termination, the Company shall pay to Executiveall amounts earned or accrued through the Qualified Termination date,including, without limitation (a) base salary, (b) a prorated portion of anyearned incentive compensation, (c) compensation for unused paid time off, and(d) reimbursement for reasonable and necessary expenses incurred by Executiveon behalf of the Company during the period ending on the Qualified Terminationdate.  Company shall also pay Executivean amount equal to two hundred  percent (200%)of Executive’s annual base salary, plus two hundred percent (200%) of Executive’sannual incentive compensation target (excluding commission targets), determinedat the time of the Qualified Termination or as of the date of the Change inControl, or determined on the basis of Executive’s prior calendar year’scompensation, whichever is greater (***“Severance Compensation”***).  Severance Compensation shall be payable overa twenty-four (24) month period (the ***“Severance Period”***)in bi-weekly equal installments, beginning on the Company’s next applicablepayroll period following the Qualified Termination date.

Executiveshall not be required to mitigate the amount of any payment provided for inthis Agreement by seeking other employment or otherwise, and no such paymentshall be offset or reduced by the amount of any compensation or benefitsprovided to Executive in any subsequent employment.

(2)                                  Allreference to the terms “Severance Period” and “Severance Compensation” in theAgreement shall have the meanings described in Section (1) above.

(3)                                  Thefollowing Section 19 is added to the Agreement:

**SECTION 409A. **The parties acknowledge and agree that theinterpretation of Section 409A and its application to the terms of thisAgreement is uncertain and may be subject to change as additional guidance andinterpretations become available. Anything to contrary herein notwithstanding, all benefits or paymentsprovided by the Company to the Executive that would be deemed to constitute “nonqualifieddeferred compensation” within the meaning of Section 409A are intended tocomply with Section 409A.  If, however,any such benefit or payment is deemed not to comply with Section 409A, the 

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Company and the Executive agree to renegotiate in goodfaith any such benefit or payment (including, without limitation, as to thetiming of any severance payment payable hereof) so that either (a) Section 409Awill not apply or (b) compliance with Section 409A will be achieved; provided,however, that any resulting renegotiated terms shall provide to the Executivethe after-tax economic equivalent of what otherwise has been provided to theExecutive pursuant to the terms of this Agreement, and provided further, thatany deferral of payments or other benefits shall be only for such time periodas may be required to comply with Section 409A.

All the remainingterms and conditions of the Agreement shall continue in full force and effect.

 
| **Evolving Systems, Inc.**      |                |
|---------------------------------|---------------------|
| ** **                      |                |
| By:                             |                | /s/ Anita T. Moseley |   |
|                            |                |   |   |
| Name:                           |                | Anita T. Moseley |   |
|                            |                |   |   |
| Title:                          |                | Sr. Vice President |   |
| ** **                      |                |
| ** **                      |                |
| **Executive:  BRIAN R. ERVINE** |                |
| ** **                      |                |
| ** **                      |                |
|                            | /s/ Brian R. Ervine |   |
|                                 |                     |  |  |  |  |

 

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