HUNTLEY, Justice.
This case presents three issues: (1) whether the district court employed the appropriate standard of review for an administrative proceeding under the Education for All Handicapped Children Act (EAHCA); (2) whether the Boise Independent School District fulfilled its legal obligation to offer Thornock a Free Appropriate Public Education (FAPE); (3) whether the school district’s duty to provide a FAPE is obviated because of Thornock’s parent’s selection of private school placement for their son.
Gabriel Thornock, a multiply handicapped child, is the son of Lana Baugh and has been classified as “trainable mentally retarded.” During the 1981-82 school year, Gabriel resided in the Meridian School District, where he was placed in the public school’s “contained classroom,” a class consisting solely of handicapped children taught by special education teachers. Gabriel’s parents decided to place him in a private school to better attain social integration and achievement goals. All of the private schools contacted by his parents required that he have the assistance of a full time one-to-one aide. They enrolled him in St. Joseph’s parochial school in the Boise School District for the 1982-83 school year.
Once Gabriel was enrolled in a private school, his parents started administrative proceedings to obtain reimbursement for the one-to-one aide.
Since Gabriel’s legal residence was still in the Meridian School District, Meridian contracted with the Boise School District to provide special education services. In June 1988, the Thornocks changed their residence to the Boise School District. Gabriel’s parents requested the Boise School District to provide special education related services including publicly funded services of a full time one-to-one aide.
On August 29, 1983, a Child Study Team (CST) meeting was convened to develop a program of special education related services and discuss the financial responsibility for the full time one-to-one aide.
The Boise Independent School District had been advised by its legal counsel that it was not financially responsible for the services of a full time one-to-one aide provided in a private school setting. On November 15, 1983, the Child Study Team meeting reconvened, meeting with Gabriel’s parents to inform them of opportunities available to Gabriel through the public education system. The district made no offer to consider any placement other than in a segregated classroom for “special education” children. Gabriel’s parents contended that he was entitled to receive “mainstreaming” under federal statute, that is, placement in a classroom with non-handicapped children. The district offered to pay for related ser[469]*469vices in a private school, but would not pay for the full time one-to-one aide. However, Gabriel’s parents chose to keep him in the private school setting and initiated administrative proceedings in which they sought reimbursement for the cost of the one-to-one aide and the tuition at the private school.
The hearing officer ruled in favor of the Boise Independent School District. The decision was appealed to the State Department of Education where the decision was affirmed. Gabriel next filed a petition in district court for judicial review of the administrative decision. The district court reversed and ruled in favor of Gabriel Thor-nock and the district now appeals.
I.
We first address whether the district court applied the appropriate standard of review under the EAHCA.
In 20 U.S.C. § 1415(e)(2), Congress states that “the court shall receive the records of the administrative proceedings, shall hear additional evidence of the request of a party, and, basing its decision on the preponderance of the evidence, shall grant such relief as the court determines is appropriate.”
The school district, citing Board of Education of the Hendrick Hudson Central School District v. Rowley, 458 U.S. 176, 102 S.Ct. 3084, 73 L.Ed.2d 690 (1982) claims that the district court’s review is not a de novo review where the decision is based on the preponderance of the evidence. Rather, the district would impose an “implied limitation” on the court’s review and require “due weight” to be given to the hearing officer’s decision.
Rowley, supra, involved a student who was mainstreamed and received passing grades in the standard program of study. The dispute in Rowley was whether the district should be using federal money to provide the student with a deaf language interpreter. Given the court’s holding that the student was receiving an appropriate education, the court understandably stated that “courts must be careful to avoid imposing their view of preferable education methods upon the states.” Rowley, 458 U.S. at 207, 102 S.Ct. at 3051.
Unlike Rowley, the instant case does not involve a school district’s choice between two appropriate educational alternatives. Rather, the question here is whether the education offered was appropriate at all. The district court did not abuse the preponderance of the evidence standard by measuring the educational policies of the school district against the Congressional requirements. The question before the district court was whether the education offered Thornock was appropriate.
Rowley required that due weight be given to the proceedings before the hearing officer. This would indicate that the evidence presented in the hearing be considered as much a part of the record as any proceedings before the district court as long as those proceedings comply with 20 U.S.C. § 1415. It does not imply that the hearing officer’s findings and conclusions should rise beyond whatever persuasive value they have in the district court’s decision on the merits.
In Gregory K. v. Longview School Dist., 811 F.2d 1307 (9th Cir.1987), both the standard applicable to the trial court and that applicable to the appellate court in these cases was discussed. As to the deference to be given state administrative findings, the Gregory court noted:
As the Supreme Court has held, courts must give “due weight” to judgments of education policy when they review state hearings under 20 U.S.C. § 1415(e). Hendrick Hudson Dist. Bd. of Ed. v. Rowley, 458 U.S. 176, 206, 102 S.Ct. 3034, 3050, 73 L.Ed.2d 690 (1982). Citing Rowley, we have held that “courts should not substitute their own notions of sound educational policy for those of the school authorities which they review.” Wilson v. Marana Unified School Dist., 735 F.2d 1178, 1183 (9th Cir.1984). How much deference to give [470]*470state educational agencies, however, is a matter for the discretion of the courts:
The traditional test of findings being binding on the court if supported by substantial evidence, or even a preponderance of the evidence, does not apply. This does not mean, however, that the findings can be ignored. The court, in recognition of the expertise of the administrative agency, must consider the findings carefully and endeavor to respond to the hearing officer’s resolution of each material issue. After such consideration, the court is free to accept or reject the findings in part or in whole.
Town of Burlington v. Dept. of Ed., 736 F.2d 773, 792 (1st Cir.1984), aff’d, 471 U.S. 359, 105 S.Ct. 1996, 85 L.Ed.2d 385 (1985).
The district court in the instant case noted:
[TJhat the school district’s argument is irrelevant to the outcome of this case. The evidence in this case, unlike most cases, is clear and uncontroverted as to every relevant fact. By any standard of evidentiary review this Court’s ruling would have to be the same as is herein announced.
The Boise School District put forth no evidence rebutting the substantial evidence that mainstreaming was appropriate for Gabriel.
As to this Court’s standard of review, the Court in Gregory, supra, commented:
The Court of Appeals reviews the district court’s findings of fact for clear error. Burlington Northern, Inc., v. Weyerhaeuser Co., 719 F.2d 304, 307 (9th Cir.1983). “A finding of fact is deemed clearly erroneous when although there is evidence to support it, the reviewing court is left with a definite and firm conviction that a mistake has been made.” Id. Even where, as here, the district court relies on a written record of administrative proceedings, the clearly erroneous standard applies to findings of fact. Id.
The Court of Appeals reviews de novo the district court’s conclusions of law. Id. Unless a mixed question of fact and law is primarily factual, we review mixed questions de novo. United States v. McConney, 728 F.2d 1195, 1199-1204 (9th Cir.) (en banc), cert. denied, 469 U.S. 824, 105 S.Ct. 101, 83 L.Ed.2d 46 (1984). For example, whether the school district’s proposed IEP was a “free appropriate public education” as required by the Education for all Handicapped Children Act is a mixed question that we review de novo. Wilson v. Marana Unified School District, 735 F.2d 1178, 1181 (9th Cir.1984); Department of Education, State of Hawaii v. Katherine D., 727 F.2d 809, 814 n. 2 (9th Cir.1983), cert. denied, 471 U.S. 1117, 105 S.Ct. 2360, 86 L.Ed.2d 260 (1985).
The district court followed the standard of review provided in 20 U.S.C. § 1415, and there is no showing that it violated the preponderance of evidence standard by finding that the education offered by the Boise School District was not appropriate.
II.
With the appellate court standard of review enunciated in Gregory, supra, in mind, we now pass on to the major issue on appeal, which is whether the district court erred in ruling that the school district failed to offer Gabriel a FAPE. The purpose of the EAHCA is to make available to all handicapped children a free appropriate public education. 20 U.S.C. § 1400(c). A FAPE must be provided in the least restrive environment, and Congress has expressed a strong preference for mainstreaming handicapped children in non-handicapped educational settings. 20 U.S. C. § 1412(5)(B). Above all else, though, Congress recognized that handicapped children are unique and that placement decisions must be made on an individual basis, by a multidisciplinary team, according to a variety of criteria, not according solely to I.Q. or some other criterion. See 20 U.S.C. § 1412(5)(C) and 34 C.F.R. § 300.532. The [471]*471critical feature of any FAPE is that it must be in conformity with a handicapped child’s “individual education program” (IEP). See 20 U.S.C. § 1401(18) (FAPE defined in terms of conformity with IEP).
The importance of the IEP cannot be understated. It is the decision-making document. Accordingly, an IEP must be in effect before special education and related services are provided to a child, and it must be implemented as soon as possible following the child study team meeting. 34 C.F. R. § 300.342(b). See also, 34 C.F.R. §§ 300.342-300.345 and IDAPA 08.02.E.15, 3.e, which explain the child study team. Further, the EAHCA mandates that each local educational agency “will establish, or revise, whichever is appropriate, an individualized education program for each handicapped child at the beginning of each school year ...” 20 U.S.C. § 1414(a)(5) (emphasis added).
Just what, then, must a valid IEP contain? The EAHCA provides the answer:
“The term ‘individualized education program’ means a written statement for each handicapped child developed in any meeting by a representative of the local educational agency or an intermediate educational unit who shall be qualified to provide, or supervise the provision of, specially designed instruction to meet the unique needs of handicapped children, the teacher, the parents or guardian of such child, and, whenever appropriate, such child, which statement shall include (A) a statement of the present levels of educational performance of such child, (B) a statement of annual goals, including short-term instructional objectives, (C) a statement of the specific educational services to be provided to such child, and the extent to which such child will be able to participate in regular educational programs, (D) the projected date for initiation and anticipated duration of such services, and (E) appropriate objective criteria and evaluation procedures and schedules for determining, on at least an annual basis, whether instructional objectives are being achieved.”
20 U.S.C. § 1401(19) (emphasis added). See also 34 C.F.R. §§ 300-340-300.349; and IDAPA 08.02.E.15, 3.h and i.
Presumably to assure compliance with the least restrictive environment requirement, the EAHCA and the federal regulations require that the IEP contain a statement of the extent to which the child will be able to participate in regular educational programs. See citations above. The Idaho regulations require, inter alia, a statement of:
“the extent to which the student will participate in the regular education program and assurance by the Child Study Team that all educational alternatives have been considered and that any special education and related services to be provided for the child will be in the least restrictive environment.” IDAPA 08.02.-E.15, 3.h.v.(d).
The EAHCA makes clear that the fundamental prerequisite of any FAPE is a sufficient IEP. 20 U.S.C. § 1401(18). The legislative history and the commentators all indicate that the procedural aspects of the EAHCA are just as important as its substantive provisions, so the concern regarding the timing and the sufficiency of Gabriel’s IEP is not mere quibbling.
The dispute between Gabriel’s parents and the school district centers upon the extent to which mainstreaming is appropriate and feasible for Gabriel. In August of 1983, Gabriel’s parents initiated discussions with the school district to have one-to-one services provided in a regular classroom. The hearing officer found that from the outset Gabriel’s parents were committed to placement in St. Joseph’s and that “[f]rom the outset, the district objected to public funding of the one-to-one individual aide for Gabriel in private placement.” See Hearing Officer’s “Findings, Conclusions, and Decision,” pp. 9-10. Various letters in the record indicate that, though Gabriel’s parents authorized the release of information concerning Gabriel to the school district for evaluation, and though Gabriel was also made available to the school dis[472]*472trict for evaluation, no sufficient IEP was in effect for Gabriel at the beginning of the 1983-1984 school year.
A purported IEP was prepared by the school district on August 29, 1983, and another on November 11, 1983. Both documents suggest that the proper FAPE for Gabriel is physical and occupational therapy, and communication disorder services. However, neither document sets forth goals, objectives and “appropriate objective criteria and evaluation procedures and schedules for determining, on at least an annual basis, whether instructional objectives are being achieved” as required by 20 U.S.C. § 1401(19). Nor do they contain a statement of the extent to which Gabriel “will be able to participate in regular educational programs.” 20 U.S.C. § 1401(19)(C) (emphasis added).1 The necessity of this latter statement is made clear by 34 C.F.R. § 800.550(b):
“Each public agency shall insure:
“(1) That to the maximum extent appropriate, handicapped children, including children in public or private institutions or other care facilities, are educated with children who are not handicapped, and
“(2) That special classes, separate schooling or other removal of handicapped children from the regular educational environment occurs only when the nature or severity of the handicapped is such that education in regular classes with the use of supplementary aids and services cannot be achieved satisfactorily.”
A mere conclusory statement that the child study team has selected the least restrictive environment is not enough. There must be a statement describing the handicapped child’s ability or inability to participate in regular educational programs.
We do not hold that a new IEP must be prepared for each school year. But here, the District utterly failed to tender any appropriate IEP for Gabriel.
In a letter to the District dated November 21, 1983, Gabriel’s mother and attorney correctly informed the District that the District’s latest offer of placement was not the “least restrictive” that would be “appropriate,” and to initiate the due process hearing procedures to which they were entitled. At this point, the District was certainly obligated to tender a valid IEP. However, counsel for the District admits that, by that point, the District felt it owed no further obligation to the Thornocks. The District seemed to be operating from the erroneous premise that, regardless of the express mandate of 20 U.S.C. § 1412(5), in any given situation, the offering of an education for which the District at least partially paid (i.e. providing “comparable” Part B funded services) was all that was required of it. The District was not alone in its confusion, as the hearing officer also erroneously concluded that:
Under the provisions of the Act and the regulations applicable to this case, Boise School District is not obligated to provide to Petitioner a free appropriate public education. Rather, the District is required to provide an opportunity for equitable participation in Part B funded program benefits consistent with the number of eligible private school students and their needs.
(Hearing Officer’s “Findings, Conclusions, and Decision,” p. 13).
Because of the flaws in Gabriel’s “IEPs,” the district’s failure to acknowledge the deficiencies of the IEPs it promulgated, its failure to develop an adequate IEP after receiving notice of its noncompliance with the EAHCA in the letter of November 21, 1983, and the obvious flaw in the “Findings, Conclusions and Decision” of the Hearing Officer (i.e. stating that Gabriel was not owed a Free Appropriate [473]*473Public Education), we affirm the decision of the district court. Without a valid IEP there can be no FAPE, see 20 U.S.C. § 1401(18), and therefore 34 C.F.R. § 800.403(a)2 indicates that reimbursement is appropriate.
While our holding that no adequate IEP was prepared obviates the need to address the proper definition of “appropriate education,” we would like to provide some guidance in this area. 20 U.S.C. § 1412(5) requires all states to establish the following:
Eligibility requirements.
(5) The state has established (a) procedural safeguards as required by § 1415 of this title, (b) procedures to assure that, to the maximum extent appropriate, handicapped children, including children of public or private institutions or other care facilities, are educated with children who are not handicapped, and that special classes, separate schooling, or other removal of handicapped children from the regular educational environment occurs only when the nature or severity of the handicapped is such that education in a regular class with the use of supplementary aides and services cannot be achieved satisfactorily, ... (Emphasis added).
There is some confusion in applying the above section since the EAHCA covers all types of handicaps.3 The school district interpreted § 1412(5) to apply only to physical handicaps. The school district bases its interpretation of the section on Rowley, supra, which referred to regular examination and yearly advancement from grade to grade as a factor to consider in determining whether the education being provided was appropriate. The school district concluded that Rowley meant that mainstreaming is only appropriate when the handicapped child can progress from grade to grade. However, the Supreme Court in Rowley confined its analysis to the factual setting of that specific case. To apply the school district’s interpretation of Rowley would deprive most mentally handicapped students of the benefits of mainstreaming. The district court herein interpreted Row-ley to mean, and we agree, that when a physically handicapped student is participating in a regular curriculum, is being educated with non-handicapped students, and is achieving passing grades, a strong presumption is made that the education provided is appropriate. Rowley, 458 U.S. at 202-204, 102 S.Ct. at 3049.
In adopting the EAHCA, Congress did not distinguish between physically and mentally handicapped. In addition, Congress has indicated a strong preference for mainstreaming all handicapped children.4 Indeed, the language in 20 U.S.C. § 1415 indicates more than a mere preference for mainstreaming — but requires it “to the maximum extent appropriate.” In Wilson v. Marana Unified School Dist. of Pima [474]*474County, 735 F.2d 1178 (9th Cir.1984), the Ninth Circuit further interpreted the federal mandate to “mainstream to the maximum extent possible” as an important “policy which must be balanced with the primary objective of providing handicapped children with an ‘appropriate education’.” Id. at 1183. (Emphasis added). Therefore, mainstreaming is a major and important factor to be balanced in assessing an appropriate placement. Other factors of course include the child’s emotional and intellectual make-up.
With this definition of an “appropriate education” as a foundation, we would also like to comment on the testimony presented at the evidentiary hearing by Boise School District.
The school district argued that its segregated education was appropriate — an argument that is entirely irrelevant and superfluous to any discussion of the real issue in this case. The school district, in accepting federal funds provided under the EAHCA, has legally obligated itself to accept mainstreaming, “to the maximum extent appropriate,” as a requirement of an appropriate education. In Campbell v. Talladega County Board of Education, 518 F.Supp. 47 (N.D.Ala.1981), the court noted that although the school district questioned the soundness of the mainstreaming approach to the education of the handicapped, by accepting federal funds, “the state of Alabama has bound itself to act in accordance with that philosophy.” Id. at 55. In Roncker v. Walter, 700 F.2d 1058 (6th Cir.1983), the court stated: The perception that a segregated institution is academically superior for a handicapped child may reflect no more than a basic disagreement with the mainstreaming concept. Such a disagreement is not, of course, any basis for not following the act’s mandate. Id. at 1063. By arguing that its segregated education is appropriate for Gabriel, the Boise School District has ignored what the Alabama Supreme Court and 6th Circuit recognized. Such arguments express only a basic disagreement with the Congressional intent that mainstreaming, to the maximum extent appropriate, is preferable to an appropriate segregated education.5
III.
We next address the issue of whether the school district’s duty to provide a Free Appropriate Public Education is obviated by the selection of a private school by Gabriel’s parents. The Thornocks moved to the Boise Public School District weeks before the 1983-84 school year started and Gabriel had been enrolled in St. Joseph’s School prior to the move. As the trial court noted, it would not have been reasonable to require them to abandon his placement at St. Joseph’s School without an offer of an appropriate education elsewhere. 20 U.S.C. § 1415(e)(3) states that during the IEP review process “the child shall remain in the then current educational placement....”
Congressional preference for continuity in placement, and the failure of the [475]*475school district to offer Gabriel an appropriate education, gave his parents justification to maintain the St. Joseph’s placement without waiving his right to a Free Appropriate Public Education. It seems that a significant consideration behind the hearing officer’s decision was the fact that Gabriel’s parents had unilaterally placed Gabriel in St. Joseph’s, and that regardless of the educational program offered by the school district, it appeared Gabriel’s parents would choose to keep Gabriel in St. Joseph’s. Because of this, it seems the hearing officer and the school district might have believed the obligation of the school district to develop an IEP and provide a FAPE was somehow lessened. We would like to dispel any such notion.
The EAHCA vests the state educational agency with responsibility for carrying out its mandates:
“The State educational agency shall be responsible for assuring that the requirements of this part are carried out and that all educational programs for handicapped children within the State, including all such programs administered by any other State or local agency, will be under the general supervision of the persons responsible for educational programs for handicapped children in the State educational agency and shall meet educational standards of the State educational agency.”
20 U.S.C. § 1412(6) (emphasis added).
A California court in Nevada County Office of Educ. v. Super. of Pub. Instruction, 149 Cal.App.3d 767, 197 Cal.Rptr. 152, 158 (1983), explains further:
“The intent of establishing a single line of responsibility is clear. Referring to the rule that the state education agency must bear ultimate responsibility, the comment to the EAHCA states, ‘The Committee considers the establishment of single agency responsibility for assuring the right to education of all handicapped children of paramount importance. Without this requirement, there is an abdication of responsibility for the education of handicapped children. Presently, in many States, responsibility is divided, depending upon the age of the handicapped child, sources of funding, and type of services delivered_ the responsibility must remain in a central agency overseeing the education of handicapped children, so that failure to deliver services or the violation of the rights of handicapped children is squarely the responsibility of one agency.’ (Sen.Rep. No. 94-168, 1st Sess., p. 24 (1975); 1975 U.S.Code Cong. & Admin.News, at p. 1448.)”
The school district cannot abdicate its vital role merely because Gabriel is enrolled in a private school. The EAHCA requires the state to develop a plan setting forth policies to assure that “all children residing in the state who are handicapped, regardless of the severity of their handicap, and who are in need of special education and related services are identified, located, and evaluated_” 20 U.S. C. § 1412(2)(C) (emphasis added). Even if a child is placed in a private school unilaterally by his or her parents, the state educational agency must ensure that an IEP is developed and implemented for the child if the child “[i]s enrolled in a parochial or other private school and receives special education or related services from a public agency.” 34 C.F.R. § 300.341(b)(2)6. Here, Gabriel was receiving special education from the school district while attending St. Joseph’s, and therefore, the school district was required to develop or revise Gabriel’s IEP and take steps to implement [476]*476it. The responsibility rested with the district, not St. Joseph’s or Gabriel's parents.
The school district has an affirmative obligation to offer a Free Appropriate Public Education. If the burden were placed on the parents of handicapped children to solicit appropriate educational offers from-the district, it would be possible for two handicapped children in identical circumstances to be given opposing benefits, the difference between the two being the willingness of one parent to force the school district to make an offer and the other parents’ unwillingness to pursue such a course. We cannot imagine Congress intending such an inequitable result.
The district court correctly ruled that the school district has an affirmative duty to offer a Free Appropriate Public Education to all handicapped children. Hawaii Department of Education v. Katherine D., 727 F.2d 809 (9th Cir.1983), cert. den., 471 U.S. 1117, 105 S.Ct. 2360, 86 L.Ed.2d 260 (1985).
By affirming the district court, we do not mean to denigrate the expertise of the school authorities for determination as to the appropriateness of various forms of education. Courts must consider the determinations of school authorities regarding the most appropriate form of education and courts must recognize that the school authorities may validly find mainstreaming inappropriate where the educational experience would/could not be productive or enriching to the student, or where it would disrupt the classroom.
Here, however, the school district failed to prepare a valid I.E.P., the necessary precursor to an offer of a FAPE, for the 1983-84 and 1984-85 school years. Additionally, the school district expressed a preference for its own system of segregated education, presented evidence of its efficacy and offered no rebuttal evidence regarding the appropriateness of mainstreaming for Gabriel. Having accepted federal funding under the EAHCA, the district is obligated to treat “mainstreaming,” “to the maximum extent appropriate,” as its preference.
The final question raised by the district is whether the school district can be ordered to reimburse Gabriel’s parents for their expenses, namely tuition and full time one-to-one aide services incurred in providing him with the appropriate education the school district failed to offer him.
This question was resolved by the United States Supreme Court in Burlington School Comm. v. Mass. Dept. of Educ., 471 U.S. 359, 370, 105 S.Ct. 1996, 2003, 85 L.Ed.2d 385 (1985), where the court stated that “by empowering the court to grant ‘appropriate’ relief Congress meant to include retroactive reimbursement to parents as an available remedy in a proper case.” As the court noted, by informing parents on the one hand that they correctly placed their child in an appropriate private placement rather than accept an inappropriate public placement, but also noting that they cannot be reimbursed for their expenditures which the school district should have paid, would be to hand them a “pyrrhic victory.” See also, Hudson by and Through Tyree v. Wilson, 828 F.2d 1059 (4th Cir.1987). The school district did not develop and implement a sufficient IEP. Therefore, Gabriel was not offered a FAPE and the district court properly ordered that Gabriel’s parents be reimbursed. That Gabriel was unilaterally placed in a private school by his parents did not obviate the school district’s duty to develop and implement a sufficient IEP. Therefore, defendant Boise Independent School District No. 1 must reimburse plaintiffs for Gabriel’s tuition at St. Joseph’s School plus payments made to his one-to-one aides for the school years such benefits were denied.
The decision of the district court that Gabriel was not offered a FAPE is affirmed. The parties are hereby alerted to the fact that this decision is narrow in its scope in one respect, in that it does not preclude continued and future analysis as to the appropriate placement of Gabriel in the system in ensuing years, as the scope [477]*477of this decision is limited only to the placement which was developed as a result of the proceedings in 1983. Future child study team proceedings working toward the development of a valid IEP for Gabriel would not be prohibited by this opinion.7 Costs to respondents. No attorney fees awarded.
BISTLINE and JOHNSON, JJ., concur.