                                                  131 Nev., Advance Opinion 14
                       IN THE SUPREME COURT OF THE STATE OF NEVADA


                MICHAEL M. BLUESTEIN,                                No. 62308
                Appellant,
                vs.
                ELLEN G. BLUESTEIN, N/K/A ELLEN
                                                                          FILED
                GREEN, N/K/A ELLEN GREEN-                                 MAR 2 6 2015
                MILLER,
                Respondent.




                           Appeal from a post-divorce decree order regarding child
                custody. Eighth Judicial District Court, Family Court Division, Clark
                County; Cheryl B. Moss, Judge.
                           Reversed and remanded.



                Urban Law Firm and Seth T. Floyd, Las Vegas,
                for Appellant.

                McFarling Law Group and Emily M. McFarling, Las Vegas,
                for Respondent.




                BEFORE THE COURT EN BANC.


                                                 OPINION


                By the Court, DOUGLAS, J.:
                           In this child custody case, the parties entered into an
                agreement for joint custody at the time of their divorce, and seven years
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                later the mother requested that the district court modify the child custody
                designation to provide her with primary physical custody, so as to modify
                child support, in accordance with Rivero v. Rivero, 125 Nev. 410, 216 P.3d
                213 (2009).    River° established a workable formula to assist courts in
                determining when a joint physical custody arrangement exists by
                providing that if each parent had physical custody of the child at least 40
                percent of the time, they shared joint physical custody. Here, the mother
                requested that the district court modify the joint custody designation to
                provide her with primary physical custody because the father did not have
                the child at least 40 percent of the time under the parties' custodial
                agreement. The district court granted the mother's request based on the
                amount of time the father had the child each week but failed to consider
                whether the modification was in the child's best interest.
                              We hold that a district court has authority to review and
                modify a custodial agreement once a modification request is made by
                either party. We further hold that the child's best interest must be the
                primary consideration for modifying custody and Rivero's 40-percent
                guideline shall serve as a tool in determining what custody arrangement is
                in the child's best interest. Because the district court did not consider the
                child's best interest when modifying custody, we reverse and remand for
                further proceedings.

                                  FACTS AND PROCEDURAL HISTORY

                              Ellen and Michael Bluestein were married for 13 years and
                had one child together. In 2004, they entered a stipulated divorce decree,
                which provided that Michael would have the child from 5 p.m. on
                Thursday to 9:30 a.m. on Sunday, Ellen would have the child the rest of

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                the week, and the parties would alternate custody on holidays. The decree
                did not identify whether this arrangement was joint or primary physical
                custody, but one month after the divorce decree was entered, the parties
                filed a parenting agreement that was adopted by the court and provided
                that they shared joint legal and physical custody of the child. As for child
                support, it was not addressed in either the divorce decree or the parenting
                agreement, and the parties indicated that neither party was obligated to
                pay support.
                              In 2011, Michael began receiving public assistance and the
                Nevada Department of Health and Human Services, through a proceeding
                separate from the divorce matter, sought reimbursement from Ellen for a
                portion of the state aid received by Michael as her child support
                obligation.' A hearing master recommended that Ellen reimburse the
                state $82 each month for child support. Ellen objected to the master's
                recommendation and filed the underlying motion in the divorce matter
                requesting that the district court designate her as the child's primary
                physical custodian in accordance with Rivero, 125 Nev. 410, 216 P.3d 213,
                which was decided after the court adopted the parties' parenting




                      1 The physical custody arrangement governs the child support award.
                When parties share joint physical custody of a child, the higher-income
                parent is obligated to pay the lower-income parent the difference between
                the parents' statutorily calculated child support amounts. River°, 125
                Nev. at 437, 216 P.3d at 232; Wright v. Osburn, 114 Nev. 1367, 1368-69,
                970 P.2d 1071, 1072 (1998). When one parent has primary physical
                custody, the noncustodial parent must pay child support based on the
                statutory formulas. See NRS 125B.070; NRS 125B.080; Rivero, 125 Nev.
                at 436, 216 P.3d at 231.

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                   agreement. Ellen argued that Michael only had the child 38 percent of the
                   time under the agreed custodial arrangement.
                               The district court held a hearing on Ellen's motion and
                   considered, among other evidence, the child's statement that for as long as
                   the child could remember, Michael's custodial time lasted from 5 p.m. on
                   Thursdays until 9:30 a.m. on Sundays. Based on that evidence and the
                   timeshare set forth in the parties' agreement, the district court entered an
                   order concluding that Ellen had primary physical custody of the child
                   because Michael had the child only 38.393 percent of the time. The court
                   further stated that even if it were to assume that Michael picked the child
                   up from school on Thursdays, thereby adding two extra hours to his
                   weekly timeshare, his resulting total timeshare would only be 39.583
                   percent.
                               Upon Michael's motion for reconsideration, the district court
                   held an evidentiary hearing. Because Thursday was the only custodial
                   day in dispute at that point, the court heard evidence regarding the time
                   that each party spent with the child and their responsibilities regarding
                   the child on Thursdays. After the hearing, the district court entered an
                   order providing that "only one parent should be assigned as the custodial
                   parent on Thursdays... land] the mother was the primary parent who
                   provided supervision for the child and made decisions regarding the child
                   for the majority of the time on Thursdays." Thus, the court designated
                   Ellen as the child's primary physical custodian. The court's order did not
                   state whether this modification was in the child's best interest. Instead,
                   the court rested the decision on its factual determination that Ellen had
                   the child 260 days and Michael had the child 105 days in 2011, and
                   therefore, Ellen had primary physical custody. The court remanded the

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                 matter to the child support master for further determination as to child
                 support. Michael appeals and challenges the designation of Ellen as the
                 child's primary physical custodian.

                                                DISCUSSION

                 Modifying custody agreements
                             On appeal, we must decide whether the district court properly
                 modified an agreed-upon custodial arrangement in accordance with
                 River°, 125 Nev. 410, 216 P.3d 213; NRS 125.480(1); and NRS 125.510(2).
                 As a threshold matter, we must determine whether the district court
                 appropriately considered Ellen's motion when she did not request a
                 change in the parties' timeshare arrangement, and instead, only requested
                 a change in the custody designation. Michael argues that because Ellen
                 did not request a change in the actual timeshare, the district court lacked
                 authority to modify custody and should have enforced the agreement as
                 written.
                             Public policy encourages parents to enter into private custody
                 agreements for co-parenting.    See St. Mary v. Damon, 129 Nev.
                 309 P.3d 1027, 1035-36 (2013); Rennels v. Rennels, 127 Nev. „ 257
                 P.3d 396, 399 (2011). As such, parties in family law matters are free to
                 contract regarding child custody, and such agreements are generally
                 enforceable. Rivero, 125 Nev. at 429, 216 P.3d at 226-27 (acknowledging
                 that courts will generally enforce parenting agreements as long as "they
                 are not unconscionable, illegal, or in violation of public policy"). The terms
                 upon which the parties agree will control until one or both of the parties
                 move the court to modify the custody agreement.       Id. at 429, 216 P.3d at
                 226. "[O]nce parties move the court to modify an existing child custody

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                   agreement, the court must use the terms and definitions provided under
                   Nevada law, and the parties' definitions no longer control." Id. at 429, 216
                   P.3d at 227.
                                  In this case, the parties' agreement to share joint physical
                   custody controlled until Ellen filed her motion requesting that the district
                   court modify the custody agreement and designate her as the primary
                   physical custodian. While Ellen did not request a modification of the
                   actual timeshare arrangement, by requesting a modification to the
                   physical custody designation, she was asking the district court to review
                   the parties' child custody agreement and apply current Nevada law.
                   Therefore, we conclude that once Ellen filed her motion, the district court
                   had authority to review the parties' timeshare arrangement, determine
                   whether the parties shared joint physical custody under Nevada law, and
                   modify the agreement accordingly. See Rennels, 127 Nev. at , 257 P.3d
                   at 399 (explaining that this court reviews purely legal matters de novo).

                   Child's best interest is paramount when modifying custody
                                  Once the issue of custody is brought before the court, the
                   standards under Nevada law for modifying custody control. When
                   modifying a joint custody agreement, the court must consider whether
                   such modification is in the child's best interest. NRS 125.510(2). Instead
                   of considering the child's best interest in interpreting and modifying the
                   parties' custodial arrangement here, the district court applied Rivero's 40-
                   percent guideline to determine if Michael had the child at least 40 percent
                   of the time, and therefore, shared joint physical custody of the child with
                   Ellen without considering the child's best interest.
                                  In River°, the parties had agreed to joint physical custody
                   during their divorce but had created a timeshare arrangement where the
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                 mother had the child five days each week. 125 Nev. at 418, 216 P.3d at
                 219. A year after the divorce, the mother filed a motion requesting that
                 the court recognize that she had de facto primary physical custody or, in
                 the alternative, modify custody.      Id.   The father filed a countermotion
                 requesting a modification to the timeshare arrangement to reflect the
                 parties' agreement to share joint physical custody. Id. The district court
                 concluded that the parties had intended a joint physical custody
                 arrangement and thus ordered a modification to give the parties an equal
                 timeshare. Id. at 419, 216 P.3d at 220.
                             On appeal, in recognizing that the Nevada Legislature had not
                 explicitly defined joint custody, this court set forth parameters for the
                 purpose of clarifying which timeshare arrangements qualified as joint
                 physical custody.   Id. at 423, 216 P.3d at 222-23. This court began by
                 recognizing that "[fin determining custody of a minor child . . . the sole
                 consideration of the court is the best interest of the child." Id. at 423, 216
                 P.3d at 223 (alteration in original) (quoting NRS 125.480(1)). Further, it
                 is in the child's best interest to "have frequent associations and a
                 continuing relationship with both parents. . . and It] o encourage such
                 parents to share the rights and responsibilities of child rearing."        Id.
                 (alterations in original) (quoting NRS 125.460). As such, there is a
                 presumption that joint physical custody is in the best interest of the child
                 if the parties agree. Id.; NRS 125.490(1). While a joint physical custody
                 arrangement presumes a 50/50 timeshare, this court acknowledged that
                 "there must be some flexibility in the timeshare requirement." Rivero, 125
                 Nev. at 424-25, 216 P.3d at 223-24.
                             River° provided a guideline to assist courts in determining
                 when a timeshare arrangement qualifies as joint physical custody. Id. at

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                  426, 216 P.3d at 224 (explaining that "we adopt this guideline to provide
                  needed clarity for the district courts" (emphasis added)). This court held
                  that if each parent had physical custody of the child at least 40 percent of
                  the time, equal to at least 146 days over one calendar year, the parents
                  shared joint physical custody. Id. at 427, 216 P.3d at 225. Regardless of
                  this guideline, we reiterated that in custody matters, the child's best
                  interest is paramount.    Id. (providing that "absent evidence that joint
                  physical custody is not in the best interest of the child, if each parent has
                  physical custody of the child at least 40 percent of the time, then the
                  arrangement is one of joint physical custody").
                               In this case, the district court strictly applied Rivero's 40-
                  percent guideline as the sole factor in deciding Ellen's motion to modify
                  the parties' custody agreement. Absent from the court's order was any
                  findings or evaluation of whether the modification is in the child's best
                  interest.   See NRS 125.510(2) (prohibiting a modification of a custodial
                  arrangement unless the modification is in the child's best interest).
                  Instead, the court focused on the exact time each parent spent with the
                  child to arrive at the conclusion that Michael had physical custody just a
                  fraction short of 40 percent, and thus, Ellen was the child's primary
                  physical custodian.
                               We take this opportunity to clarify that our decision in Rivero
                  was intended to provide consistency in child custody determinations, but it
                  was never meant to abrogate the court's focus on the child's best interest.
                  Thus, Rivero's 40-percent guideline should not be so rigidly applied that it
                  would preclude joint physical custody when the court has determined in
                  the exercise of its broad discretion that such a custodial designation is in
                  the child's best interest. See Ellis v. Carucci, 123 Nev. 145, 149, 161 P.3d

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                  239, 241 (2007) (providing that the district court has broad discretionary
                  powers when resolving issues of child custody). Considering the child's
                  best interest is especially important in a case such as this where the
                  district court has determined that one parent has the child almost 40
                  percent of the time and the timeshare allows the child frequent
                  associations with both parents.       See NRS 125.460(1) (providing that
                  Nevada's policy is to "ensure that minor children have frequent
                  associations and a continuing relationship with both parents after the
                  parents. . . have dissolved their marriage"). Further, when a party is
                  seeking a modification to the custodial designation solely to receive a
                  decrease in his or her child support obligation, it is vital that the district
                  court consider whether such modification is in the child's best interest.
                  See, e.g., River°, 125 Nev. at 431, 216 P.3d at 228 (explaining that the
                  district court can modify a child support order if there has been a change
                  in circumstances and such modification is in the best interest of the child);
                  see also NRS 125B.030 (providing that the parent with physical custody
                  may recover child support from the noncustodial parent).
                               Here, the district court abused its discretion by failing to set
                  forth specific findings that modifying the parties' custodial agreement to
                  designate Ellen as primary physical custodian was in the best interest of
                  the child.   Wallace v. Wallace, 112 Nev. 1015, 1019, 922 P.2d 541, 543




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             ea
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                 (1996) (this court reviews a district court's decision concerning custody for
                 an abuse of discretion). On that basis, we reverse the district court's order
                 and remand for further proceedings consistent with this opinion



                                                                                        ,   J.
                                                            Douglas

                 We concur:


                                              , C.J.
                 Hardesty



                 Parragui rre




                                                 J.
                 Saitta,




                 (91 de
                 Pickering
                                                 J.




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