Dissent by Judge BEA
OPINION
PER CURIAM:We consider whether the district court erred in affirming an administrative officer’s determination that J.B., an autistic student protected by the Individuals with Disabilities Education Act (“IDEA”), was denied a free appropriate public education (“FAPE”).
FACTS
Before and during this lawsuit, J.B. attended the Pacific Autism Center (“PAC”), a small private school for students with autism and other special needs. During that time, Hawaii Department of Education (“DOE”) personnel convened to develop an Individualized Education Plan (“IEP”) for J.B.’s transition from PAC into public kindergarten. J.B. raised various objections to aspects of the proposed IEP, but the presiding administrative hearings officer found that the IEP was adequate. J.B. appeals from the district court’s affirmation of that determination.
DISCUSSION
As a threshold matter, DOE claims this case is now moot because J.B. received relief beyond that originally requested. J.B. initially sought reimbursement of PAC tuition for the 2012-13 school year, and DOE funded J.B.’s tuition at PAC from 2012 until 2015. But a case is moot “only when it is impossible for a court to grant any effectual relief whatever to the prevailing party.” Decker v. Nw. Envtl. Def. Ctr., 568 U.S. 597, 133 S.Ct. 1326, 1335, 185 L.Ed.2d 447 (2013) (citation omitted). J.B.’s due process complaint sought reimbursement for transportation and compensatory education, in addition to reimbursement for tuition at PAC. Because we can still grant effectual relief, this case is not moot.
Turning to J.B.’s specific objections to the proposed IEP, he first argues that DOE violated the IDEA procedurally by refusing to address his father’s concerns about the transition from PAC to a public school. Some Hawaii district courts have noted that the IDEA mentions transition services only with respect to students exiting the public school system, 20 U.S.C. § 1414(d)(1)(A)(i)(VIII)(bb), and thus inferred that transition services need not be provided at any other time. See J.M. v. Dep’t of Educ., Haw., 224 F.Supp.3d 1071, 1091 (D. Haw. 2016); Rachel L. v. Haw. Dep’t of Educ., No. 11-00756, 2012 WL 4472263, at *7 (D. Haw. Sept. 25, 2012) (collecting cases). However, these opinions have read the IDEA too narrowly and are to that extent overruled. The statute provides that IEPs must include “supplementary aids and services” that will allow children to “be educated and participate with other children with disabilities and nondis-abled children!.]” 20 U.S.C. § 1414(d)(1)(A)(i)(IV). Services that ease the transition between institutions or programs—whether public or private—serve this purpose. Cf. Cal. Educ. Code § 56345(b) (codifying this broader interpretation of IDEA requirements). Where transition services become necessary for disabled children to “be educated and participate” in new academic environments, transition services must be included in IEPs in order to satisfy the IDEA’S “supplementary aids and services” requirement,
; Here, J.B.’s father’s transition-related concerns centered on the “needed modifications to offset the changes anticipated in J.B.’s program, such as the number of peers or daily routines available to him[.]” J.B. was planning to move from a private school into the public school system for the first time, and these considerations were relevant to his educational participation with other children. Thus, DOE violated the IDEA by failing to address transition services in the proposed IEP.
Second, J.B. claims that DOE violated the IDEA by failing to specify in the IEP the Least Restrictive Environment (“LRE”) during the regular and extended school year. The IEP “must include ... [a]n explanation of the extent, if any, to which the child will riot participate with nondisabled children in the regular class” and “the anticipated frequency, location, and duration of [the special education] services arid modifications.” 34 C.F.R. § 300.320(a)(5), (7). J.B.’s IEP contained only the vague statement that J.B. would “receive specialized instruction in the general education setting for Science and Social Studies activities as deemed appropriate by his Special Education teacher/Care Coordinator and General Education teacher.” This improperly delegated the determination of J.B.’s placement to teachers outside the IEP process. The language was also too vague to enable J.B. to use the IEP as a blueprint for enforcement. See Union Sch. Dist. v. Smith, 15 F.3d 1519, 1526 (9th Cir. 1994) (“[A] formal, specific offer from a school district will greatly assist parents in ‘presént[ing] complaints with respect to any matter relating to the ... educational placement of the child.’ ”) (second alteration in original) (emphasis added) (citation omitted).
Moreover, the IEP didn’t detail “the anticipated frequency, location, and duration” of the proposed specialized instruction in J,B.’s Science and Social Studies activities, as required by 34 C.F.R. § 300.320(a)(7). This fails to meet the legally required threshold of specificity. DOE further- failed to discuss appropriately “(1) the educational benefits of placement full-time in a regular class; (2) the non-academic benefits of such placement; (3) the effect [J.B.] had on the teacher and children in the regular class; and (4) the costs of mainstreaming [J.B.].” Sacramento City Unified Sch.. Dist., Bd. of Educ. v. Rachel H. ex rel. Holland, 14 F.3d 1398, 1404 (9th Cir. 1994). DOE’s cursory treatment of the Rachel H. factors was demonstrated by J.B.’s being mainstreamed into Mandarin—a class obviously inappropriate for him—but not into Science or Social Studies. This “seriously infringe[d]” J.B.’s father’s opportunity to participate in the IEP process and was therefore a denial of a FAPE. See Doug C. v. Haw. Dep’t of Educ., 720 F.3d 1038, 1043 (9th Cir. 2013) (citation omitted).'
Third, according to J.B., the IDEA required DOE to specify- in the IEP that J.B.’s one-on-one aide would have the same qualifications as a „ contracted skills worker. But “[n]othing in [20 U.S.C. § 1414(d)] indicates that an IEP must specify the qualifications or training of service providers.” S.M. v. Haw. Dep’t of Educ., 808 F.Supp.2d 1269, 1274 (D. Haw. 2011). Nor is it established in the record that DOE agreed to provide such an aide at the IEP meeting.
Finally, J.B; argues that DOE violated the IDEA by failing to specify Applied Behavioral Analysis- (“ABA”) as a methodology in the IEP. DOE relies on our decision in J.L. v. Mercer Island Sch. Dist., 592 F.3d 938, 952 (9th Cir. 2010), to argue that this was not required. But J.L. recognized that “school districts, should specify a teaching methodology for some students, [while] for other students ‘IEPs may not need to address the instructional method to be used because specificity about methodology is not necessary to enable those students to receive an appropriate education.’” Id. (citation omitted). In J.L.’s case, educators found that specificity wasn’t appropriate. Id, But here,, the IEP team discussed ABA at length and recognized that it was integral to J.B.’s education. And ABA is widely recognized as a superior method for teaching children with autism. See Ariana Cemius, “No Imbecile at All”: How California Won the Autism Insurance Reform Battle, and Why Its Model Should Be Replicated in Other States, 10 Harv. L. & Pol’y Rev. 565, 570-72 (2016). "When a particular methodology plays a critical role in the student’s educational plan, it must be specified in the IEP rather than left up to individual teachers’ discretion.
The dissent contends that, because teachers. might have needed to use multiple methodologies with J.B.,, it was, unnecessary for .the IEP to mention ABA. But specifying ABA in writing would, not have precluded the use of other methodologies. It simply would have ensured-.that ABA would be consistently used in J.B.’s educational program, since even the school district acknowledged that ABA should be part of J.B.’s education. The IEP’s failure to specify ABA was thus a denial of a FAPE.
We remand to the district court for determination of the appropriate remedy.
AFFIRMED in part, REVERSED and REMANDED in part.
Costs to appellant.