Exhibit 10.6.4

Summary of 2020 Incentive Plans

On December 17, 2019, the Human Resources Committee (the “Committee”) of the
Pinnacle West Capital Corporation (“Pinnacle West”) Board of Directors (the
“Board”) approved the portion of the APS 2020 Annual Incentive Award Plan (the
“APS Plan”) that provides an incentive award opportunity for Jeffrey B. Guldner,
the Chairman of the Board, President, and Chief Executive Officer of Pinnacle
West and Arizona Public Service Company ("APS").  On December 18, 2019, the
Board, acting on the recommendation of the Committee, approved the portion of
the APS Plan that includes an incentive award opportunity for James R. Hatfield,
Executive Vice President and Chief Financial Officer of Pinnacle West and APS
and Daniel T. Froetscher, Executive Vice President, Operations of APS and the
APS 2020 Annual Incentive Award Plan for Palo Verde Employees (the “Palo Verde
Plan”), which includes an incentive award opportunity for Robert S. Bement,
Executive Vice President and Chief Nuclear Officer of APS.

No incentive payments will be awarded under the APS Plan unless Pinnacle West,
with respect to Mr. Guldner, or APS, with respect to Messrs. Hatfield and
Froetscher, each achieves a specified threshold earnings level. The award
opportunities for Mr. Guldner under the APS Plan are based on the achievement of
specified 2020 Pinnacle West earnings levels and specified business unit
performance goals.  Mr. Guldner has a target award opportunity of up to 110% of
his base salary.  Mr. Guldner may earn less or more than the target amount, up
to a maximum award opportunity of 220% of base salary, depending on the
achievement of the earnings and business unit performance goals separately or in
combination, and before adjustment for individual performance.  The business
unit performance indicators for Mr. Guldner are in the functional areas of
customer service, transmission and distribution, fossil generation, corporate
resources and performance of the Palo Verde Generating Station.

The award opportunities for Messrs. Hatfield and Froetscher under the APS Plan
are based on the achievement of specified 2020 APS earnings levels and specified
business unit performance goals.  Mr. Hatfield has a target award opportunity of
up to 75% of his base salary and Mr. Froetscher has a target award opportunity
of up to 90% of his base salary.  Messrs. Hatfield and Froetscher may earn less
or more than the target amount, up to a maximum award opportunity of 150% of
base salary for Mr. Hatfield and 180% for Mr. Froetscher, depending on the
achievement of the earnings and business unit performance goals separately or in
combination, and before adjustment for individual performance.  The business
unit performance indicators that will be considered for Messrs. Hatfield and
Froetscher are derived from the APS critical areas of focus, as provided in its
“Core” strategic framework, in the functional areas of employees, operational
excellence, and shareholder value. 

The award opportunity for Mr. Bement under the Palo Verde Plan is based on the
achievement of specified 2020 APS earnings levels and specified business unit
performance goals. No incentive payment will be awarded to Mr. Bement under the
APS earnings portion of the Palo Verde Plan unless Palo Verde achieves specified
business unit performance goals and APS achieves a target threshold earnings
level.  The business unit performance indicators for Mr. Bement under the Palo
Verde Plan are in the functional areas of employees, operational excellence,
performance improvement and shareholder value.  Mr. Bement has a target of 75%
of his base salary, and up to a maximum of 150% of his base salary, depending on
the achievement of the earnings and business unit performance goals, separately
or in combination, and before adjustment for individual performance. Effective
on January 21, 2020 when Mr. Bement transitions to Executive Vice President and
Special Advisor to the Chief Executive Officer of APS, Mr. Bement will remain
under the Palo Verde Plan with a target of 75% of his base salary. Due to Mr.
Bement’s retirement, he will receive a prorated award under the Palo Verde Plan
based on the amount of time he was actively employed during the plan year.

The Committee may adjust targets or incentive results under the APS Plan and
Palo Verde Plan to reflect unanticipated events or unusual or nonrecurring
adjustments to Pinnacle West or APS earnings (as applicable) that arise in the
APS Plan year, including Arizona Corporation Commission rate-related impacts on

--------------------------------------------------------------------------------

Exhibit 10.6.4

earnings. Any awards for Messrs. Guldner, Hatfield, Froetscher and Bement are
subject to potential forfeiture or recovery in accordance with Pinnacle West’s
Clawback Policy.