EXHIBIT 10.19

AMENDMENT NO. 6 TO THE

PIONEER NATURAL RESOURCES USA, INC.

401(k) AND MATCHING PLAN

(Amended and Restated Effective as of January 1, 2008)

THIS AMENDMENT NO. 6 is made and entered into by Pioneer Natural Resources USA,
Inc. (the “Company”):

WITNESSETH:

WHEREAS, the Company maintains the Pioneer Natural Resources USA, Inc. 401(k)
and Matching Plan (the “Plan”);

WHEREAS, pursuant to Section 8.3 of the Plan, the Benefit Plan Design Committee
(the “Committee”) of the Company maintains the authority to amend the Plan at
any time; and

WHEREAS, the Committee desires to amend the Plan to make certain discretionary
changes including (i) automatic enrollment for newly eligible employees and
those employees who did not make an affirmative election not to participate in
the Plan; (ii) automatic escalation of deferral percentages for those employees
who are automatically enrolled in the Plan and a voluntary annual increase
program for those employees who are not automatically enrolled; and
(iii) automatic reinstatement of deferrals at the end of a participant’s
hardship suspension period.

NOW THEREFORE, the Plan is hereby amended effective February 1, 2012 as follows.

 

  1. Section 2.2 of the Plan is hereby amended in its entirety as follows:

Participation.    Each Covered Employee who is eligible to participate in the
Plan may elect, in the manner prescribed by the Committee, to participate in
this Plan as soon as administratively practicable but no later than 31 days
following the completion and submission of such election. However, if a Covered
Employee who has been notified that he or she is eligible to participate in the
Plan on or after February 1, 2012 or who was notified of eligibility prior to
this date but never made an affirmative election not to participate in the Plan
who fails to return an alternate election pursuant to Section 3.1(a), Pre-Tax
Contributions will automatically begin being made on such Covered Employee’s
behalf at the rate specified in Section 3.1(a) on the later to occur of (a) the
thirtieth day following the Covered Employee’s Employment Date, (b) the
thirtieth day following the date such Covered Employee satisfies the eligibility
requirements set forth in Section 2.1, or (c) the thirtieth day following the
date such Covered Employee is notified of the Plan’s automatic enrollment
provisions in accordance with section 401(k)(13)(E)(i) of the Code. A Covered
Employee who desires to make an alternate election pursuant to Section 3.1(a)
must do so in the manner prescribed by the Committee.

 

  2. Section 2.3 is hereby added to the Plan as follows:

 

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Reemployed Participant.    Any Participant who ceases to be a Covered Employee
shall thereupon cease to be eligible to participate in the Plan; provided,
however, that if any such Participant is thereafter reemployed as a Covered
Employee, he or she shall be eligible to elect to resume participating in the
Plan as of the date of such reemployment. If such Covered Employee was
previously automatically enrolled in the Plan, then he or she will be
automatically enrolled in the Plan pursuant to Section 3.1(a). Any such Covered
Employee who made an affirmative election to participate in the Plan must
re-elect to participate in the Plan in accordance with Section 2.2.

 

  3. Section 3.1(a) of the Plan is hereby amended in its entirety as follows:

(a)    Each Participant may elect to have his or her Employer make a Pre-Tax
Contribution to the Plan on his or her behalf for each pay period in an amount
up to 80% of his or her Basic Compensation for that pay period, subject to any
other deductions from the Participant’s Basic Compensation that are required by
law or authorized by the Participant pursuant to a compensation reduction
agreement. All such contributions shall be made by uniform payroll deductions
pursuant to a compensation reduction agreement which authorizes the Employer to
pay such contributions to the Trustee on behalf of the Participant. However, for
any Participant subject to the Plan’s automatic enrollment provisions (as
described in Section 2.2) who fails to make an alternate election, Pre-Tax
Contributions will automatically begin being made on such Participant’s behalf,
in an amount equal to 3% of his or her Basic Compensation on the date specified
in Section 2.2 with respect to such Participant. In the event a Participant does
not desire to have Pre-Tax Contributions made on his or her behalf at the level
set by this Section 3.1(a), the Participant may elect a different amount up to
80% of his or her Basic Compensation in the manner prescribed by the Committee.

 

  4. Section 3.1(d) of the Plan is hereby amended in its entirety as follows:

(d)    A Participant may change the applicable percentage of such payroll (or
bonus) deductions or suspend his or her election to have Pre-Tax Contributions
and/or Pre-Tax Bonus Contributions made to the Plan at any time. Any such change
or suspension will be effective as soon as administratively practicable but no
later than 31 days following the submission of such change or submission. The
default percentage for any Participant who was automatically enrolled in the
Plan as set forth in Section 3.1(a) above will increase by a designated
percentage point each Plan Year up to a maximum of 5% beginning with March of
the Plan Year immediately following the Plan Year in which the default
percentage first applied to the Participant. Participants who were not
automatically enrolled in the Plan will have access to a voluntary default
percentage increase program.

 

  5. Section 6.6(d) of the Plan is amended in its entirety as follows:

(d)    Any provision of this Plan to the contrary notwithstanding, if a
Participant makes a hardship withdrawal, no contributions shall be made to this
Plan on behalf of such Participant for 6 months after receipt of such withdrawal
and no contributions shall

 

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be made by or on behalf of such Participant to any other deferred compensation
plan maintained by an Employer or Affiliated Company for 6 months after receipt
of such withdrawal. At the end of the 6 months, a Participant’s contributions
will resume automatically unless the Participant elects otherwise.

NOW, THEREFORE, be it further provided that except as provided above, the Plan
shall continue to read in its current state.

* * * * * * * *

IN WITNESS WHEREOF, the Company has executed this Amendment No. 6 this 12th day
of January, 2012, to be effective as specified above.

PIONEER NATURAL RESOURCES USA, INC.

By: /s/ Larry N. Paulsen

Name: Larry N. Paulsen

Title:   Vice President, Administration and

             Risk Management

 

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