FOR PUBLICATION
  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT

JOSEPH WEISSBURG; ADRIA                 
WEISSBURG,
               Plaintiffs-Appellants,        No. 08-55660
                 v.                            D.C. No.
LANCASTER SCHOOL DISTRICT; JANIS           2:07-cv-01921-
RIVERA, in her official capacity as           RGK-MAN
Director of Student Services of                OPINION
Lancaster School District,
             Defendants-Appellees.
                                        
        Appeal from the United States District Court
           for the Central District of California
        R. Gary Klausner, District Judge, Presiding

                   Argued and Submitted
           October 8, 2009—Pasadena, California

                   Filed January 14, 2010

      Before: Harry Pregerson, Stephen Reinhardt and
          Kim McLane Wardlaw, Circuit Judges.

                 Opinion by Judge Pregerson




                             1157
1160       WEISSBURG v. LANCASTER SCHOOL DISTRICT
                         COUNSEL

Diane B. Weissburg, Diane Bargara Weissburg Law Offices,
Marina del Rey, California, for the plaintiffs-appellants.

Carol J. Grogan, Schools Legal Service, Bakersfield, Califor-
nia, for the defendants-appellees.


                          OPINION

PREGERSON, Circuit Judge:

   Joseph and Adria Weissburg (“Weissburgs”) brought an
action for attorneys’ fees against Lancaster School District
(“school district”) under the Individuals with Disabilities Edu-
cation Act (“IDEA”), 20 U.S.C. § 1415(i)(3)(B), on behalf of
their child, Edward Weissburg (“Edward”). Edward is a
seven-year-old child with developmental disabilities who is
eligible for special education under the IDEA. In 2005, the
district issued an assessment that classified Edward as men-
tally retarded, but concluded that he did not display autistic
behavior. During the 2005-2006 and 2006-2007 school years,
the Weissburgs repeatedly challenged this classification with
the school district because the Weissburgs’ psychologist had
concluded that he was autistic, but not mentally retarded. The
school district declined to change Edward’s eligibility classi-
fication from mentally retarded to autistic.

   The Weissburgs filed a due process complaint under 20
U.S.C. § 1415(b)(6)(A), in which they requested a private
assessment of Edward’s disability classification at public
expense. The school district declined to provide a private
assessment, but conducted its own comprehensive assessment
of Edward’s disability on June 14, 2006. After conducting its
assessment, the school district concluded that Edward was not
autistic and maintained that Edward qualified for special edu-
              WEISSBURG v. LANCASTER SCHOOL DISTRICT                    1161
cation under the IDEA as mentally retarded. Shortly thereaf-
ter, the school district filed a due process complaint1 to obtain
a determination that its assessment of Edward’s eligibility
classification and educational needs was appropriate. This
complaint was consolidated with the Weissburgs’ complaint.

   After the consolidated due process hearing, the Administra-
tive Law Judge (“ALJ”) concluded that the June 14, 2006
assessment was appropriate, but that the disability classifica-
tion was “flawed” because Edward should have been eligible
for special education under both the mental retardation and
autism classifications. Despite the misclassification, the ALJ
determined that Edward had not been denied a free and appro-
priate public education (FAPE). In other words, even though
Edward was not classified as autistic, as he should have been,
he nonetheless received the educational benefits to which he
was entitled under IDEA.

   The first question presented in this appeal is whether the
ALJ’s conclusion that the school district misclassified Edward
qualifies the Weissburgs for attorneys’ fees under the IDEA
as a prevailing party, even though Edward was not denied a
FAPE. We hold that the Weissburgs are a prevailing party
because the change in disability classification legally entitles
Edward to instruction by teachers qualified to teach students
with both mental retardation and autism. Although Edward
did, in fact, receive instruction by a qualified teacher, prior to
the ALJ’s decision, the school district refused to recognize his
classification as autistic, and thus his legal right to such
instruction.

   Second, we consider whether the Weissburgs are ineligible
for attorneys’ fees under the IDEA because Edward’s grand-
mother, a practicing attorney, represented him. We decline to
  1
   Under the IDEA, any party may request a due process hearing when
there is a dispute about the identification, evaluation, or educational place-
ment of a child. 20 U.S.C. § 1415(b)(6)(A).
1162        WEISSBURG v. LANCASTER SCHOOL DISTRICT
extend our bright-line rule that prohibits attorney-parents
from receiving attorneys’ fees to situations where a more dis-
tant relative represents the child. Accordingly, we hold that
the Weissburgs are eligible for attorneys’ fees even though
Edward was represented by his grandmother.

I.   The Weissburgs Are a Prevailing Party Under the IDEA

   We review de novo whether a party is a prevailing party.
See V.S. v. Los Gatos-Saratoga Joint Union High Sch., 

, 1232 (9th Cir. 2007). The IDEA provides that the
court “may award reasonable attorneys’ fees as part of the
costs . . . to a prevailing party who is the parent of a child with
a disability.” 20 U.S.C. § 1415(i)(3)(B). “A prevailing party
is one who ‘succeed[s] on any significant issue in litigation
which achieves some of the benefit the parties sought in
bringing the suit.’ ” Van Duyn v. Baker Sch. Dist. 5J, 

, 825 (9th Cir. 2007) (quoting Parents of Student W.
v. Puyallup Sch. Dist., No. 3, 

, 1498 (9th Cir.
1994)). This success must materially alter the legal relation-
ship between the parties. 

of Student 

and Park v. Anaheim Union High Sch. Dist., 

, 1034-37 (9th Cir. 2006)).

   The district court concluded that the Weissburgs were not
a prevailing party because a change in disability classification
alone did not materially alter the legal relationship between
Edward and the school district. The district court found dispo-
sitive the ALJ’s conclusion that Edward had not been denied
a FAPE because the IDEA does not provide a right to proper
classification. For the reasons set forth below, we hold that
the district court erred in concluding that the Weissburgs were
not a prevailing party entitled to attorneys’ fees under the
IDEA.
             WEISSBURG v. LANCASTER SCHOOL DISTRICT                   1163
  A.    The Denial of a FAPE is Not Required for a Parent
        to Qualify as a Prevailing Party

   [1] At the threshold, we note that a student need not be
deprived of a FAPE for his parents to qualify as a prevailing
party. To hold otherwise would be contrary to Supreme Court
precedent, which provides that “[t]he touchstone of the pre-
vailing party inquiry must be the material alteration of the
legal relationship of the parties . . . .” Tex. State Teachers
Ass’n v. Garland Indep. Sch. Dist., 

, 792-93
(1989). Although the denial of a FAPE is a common basis for
conferring prevailing party status, attorneys’ fees are awarded
under many other circumstances.2 Accordingly, the ALJ’s
conclusion that the school district had not denied Edward a
FAPE should not determine whether the Weissburgs are enti-
tled to attorneys’ fees under 20 U.S.C. § 1415(i)(3)(B).

  B.    Prevailing on an Eligibility Category Determination
        Alters the Legal Relationship Between the Parties

  [2] The district court correctly determined that IDEA does
not give a student the legal right to a proper disability classifi-
cation. See 20 U.S.C. § 1412(a)(3)(B) (“Nothing in [the
IDEA] requires that children be classified by their disability
so long as each child who has a disability listed in [§ 1401]
and who, by reason of that disability, needs special education
   2
     See, e.g., Koswenda v. Flossmoor Sch. Dist. No. 161, 

, 992, 997 (N.D. Ill. 2002) (holding that parents were prevailing parties
when the ALJ granted partial relief, even though the ALJ found no denial
of a FAPE); Hall v. Detroit Pub. Sch., 

(E.D. Mich.
1993) (holding that parent was a prevailing party when her lawsuit
enabled her son to receive a timely hearing); Lillbask ex rel. Mauclaire v.
Connecticut Dep’t of Educ., No. 3:97 CV 1202 (PCD), 2006 U.S. Dist.
LEXIS 24263, at *10 (D. Conn. Mar. 17, 2006) (holding that parent was
a prevailing party because the court entered declaratory judgment provid-
ing that a hearing officer possesses jurisdiction to consider safety chal-
lenges to Individualized Education Plans, even though it would only
benefit the student in the future).
1164          WEISSBURG v. LANCASTER SCHOOL DISTRICT
and related services is regarded as a child with a disability
under [the IDEA].”). The district court erred, however, in fail-
ing to consider the legal ramifications of a change in disability
classification.

   [3] Although the IDEA does not confer a legal right to
proper disability classification, legal ramifications do arise
from a student’s disability classification. For example, special
education teachers must possess credentials specific to a
child’s primary disability.3 See Cal. Code Regs. Tit. 5,
§ 80046.5 (“Credential holders who are authorized to serve
children with disabilities must possess a credential that autho-
rizes teaching the primary disability of the pupils . . . .”).
Here, it is undisputed that Edward’s teacher was qualified to
teach children whose primary disabilities included mental
retardation and autism. Nevertheless, the question is whether
the change in Edward’s disability classification altered the
legal relationship between the parties. Absent the change in
disability classification, Edward did not have a legal right to
  3
    The school district argues that the teacher credentialing argument is
waived because it was not raised below. This argument fails. Although the
Weissburgs did not raise this argument below, they did assert a claim for
attorneys’ fees. Accordingly, the Weissburgs are free to make any argu-
ment in support of that claim on appeal. See Yee v. City of Escondido, 

, 534 (1992). See also United States v. Pallares-Galan, 

, 1095 (9th Cir. 1991) (“[T]he Supreme Court has made clear [that]
it is claims that are deemed waived or forfeited, not arguments.”).
   Moreover, an exception to waiver exists when “the issue is purely one
of law, does not affect or rely upon the factual record developed by the
parties, and will not prejudice the party against whom it is raised.” Janes
v. Wal-Mart Stores, Inc., 

, 888 n.4 (9th Cir. 2002) (citing
United States v. Patrin, 

, 712 (9th Cir. 1978)). Here, the cre-
dentialing argument is related to the ultimate question of whether the
Weissburgs are a prevailing party, which is a question of law that does not
depend on the factual record. See 

. Moreover, the
school district is not prejudiced because it briefed the merits of this argu-
ment on appeal. See Dream Palace v. County of Maricopa, 

,
1005 (9th Cir. 2004). Accordingly, we may consider the credentialing
argument.
           WEISSBURG v. LANCASTER SCHOOL DISTRICT           1165
instruction by a teacher qualified to teach a student with men-
tal retardation and autism. Before his classification was
changed, Edward could have been placed under the care and
instruction of a teacher who was not qualified to teach a stu-
dent with autism.

   [4] We hold that a change in eligibility category materially
alters the legal relationship between the parties because it
entitles Edward to placement in a classroom with a teacher
qualified to teach students with the primary disabilities of
mental retardation and autism. Although Edward did, in fact,
receive placement in the proper classroom, the school district
refused to recognize his additional primary disability of
autism, and thus his legal right to such placement, until his
eligibility category was changed. Accordingly, we hold that
the Weissburgs qualify as prevailing parties under the IDEA
and are thereby eligible for attorneys’ fees at the discretion of
the court.

II.   The IDEA Authorizes Attorneys’ Fees for Legal Ser-
      vices Provided by a Family Member Who is Not a Par-
      ent

   [5] We next consider whether the Weissburgs are ineligible
for attorneys’ fees under the IDEA because Edward’s grand-
mother, Diane B. Weissburg, represented him. In Ford v.
Long Beach Unified Sch. Dist., 

(9th Cir. 2006),
we adopted a bright line rule prohibiting attorneys’ fees for
attorney-parents who provide legal services for their own
child in proceedings brought under the IDEA. 

Accord S.N. ex rel. J.N. v. Pittsford Cent. Sch. Dist., 

(2d Cir. 2006); Woodside v. Sch. Dist. of Phila. Bd. of
Educ., 

(3d Cir. 2001); Doe v. Bd. of Educ. of
Balt. County, 

(4th Cir. 1998). We held that,
although attorney-parents will provide independent, emotion-
ally detached representation in some cases, a bright-line pro-
hibition would better serve Congress’ intent to ensure that
children with disabilities benefit from the judgment of an
1166          WEISSBURG v. LANCASTER SCHOOL DISTRICT
independent third party when their rights under the IDEA are
violated. 

.

   [6] We decline to extend this limitation on attorneys’ fees
to a grandparent who provides legal representation to his or
her grandchild in proceedings brought under the IDEA.
Unlike parents,4 who have a special role under the IDEA as
the enforcers of their children’s education rights, other rela-
tives are not so uniquely invested in IDEA proceedings. See
Schaffer ex rel. Schaffer v. Weast, 

, 53-54 (2005)
(describing the “cooperative process” that the IDEA estab-
lishes between parents and schools, and identifying the spe-
cial role that parents play in enforcing their children’s
educational rights under the IDEA). Accordingly, even
though parents are not eligible to receive attorneys’ fees when
they represent their children themselves, a parent is eligible to
receive attorneys’ fees when a non-parent relative provides
legal representation for their child. Cf. 

(rejecting the argument that a rule denying recovery of attor-
neys’ fees to parents would create an arbitrary distinction
between parents and more distant relatives because the IDEA
provides a clear statutory definition of “parent”).

   [7] Here, Edward was represented by his paternal grand-
mother. She is not his legal guardian, and there is no evidence
that she was acting in the place of his natural or adoptive par-
ent. Accordingly, the Weissburgs are eligible to receive attor-
neys’ fees for the representation provided by Edward’s
grandmother in these IDEA proceedings.
  4
    A “parent” is defined under the IDEA to include: (1) natural adoptive,
or foster parents; (2) a guardian, unless the child is a ward of the State;
or (3) an individual acting in the place of a natural or adoptive parent
(including a grandparent, stepparent, or other relative) with whom the
child lives, or an individual who is legally responsible for the child’s wel-
fare. 20 U.S.C. § 1401(23).
           WEISSBURG v. LANCASTER SCHOOL DISTRICT       1167
III.   Conclusion

  For the foregoing reasons, the district court’s judgment in
favor of the school district is REVERSED. The case is hereby
REMANDED to the district court for a calculation of the fee
award.