OPINION

FISHER, Circuit Judge:

We hold that a residential community that has continuously operated as a retirement community for persons age 55 or older can qualify for the housing for older persons exemption from the Fair Housing Act's prohibition on familial status discrimination by establishing that it currently satisfies the exemption's three statutory and regulatory criteria at the time of the alleged violation, even if the community enforced age restrictions when it first achieved compliance with the exemption's age verification requirement.

BACKGROUND

I.

In 1988, Congress amended the Fair Housing Act (FHA) and prohibited housing discrimination on account of familial status. See Fair Housing Amendments Act of 1988 (FHAA), Pub.L. No. 100-430, 102 Stat. 1619. As amended by the FHAA, the FHA broadly prohibits discrimination against families with children in connection with the sale and rental of housing. See 42 U.S.C. §§ 3604(a)-(e), 3605, 3606, 3617, 3631.1

At the same time, Congress recognized the effect these prohibitions would have on retirement communities and created exemptions in the FHA for qualified "housing for older persons." Id. § 3607(b). The housing for older persons exemptions permit communities satisfying certain requirements to discriminate on the basis of familial status. See id. The exemptions apply to three types of housing, including, as relevant here, housing for persons 55 years of age or older. See id. § 3607(b)(2)(C).2

The familial status provisions of the FHA, including the housing for older persons exemptions, became effective in March 1989. See id. § 3601 note (quoting FHAA § 13(a)). In January 1989, the Department of Housing and Urban Development (HUD) issued final regulations implementing the exemptions. See Implementation of the Fair Housing Amendments Act of 1988, 54 Fed.Reg. 3232, 3290-3291 (Jan. 23, 1989); see also 24 C.F.R. §§ 100.10(b), 100.300-100.304 (1991). A few years later, in 1995, Congress passed the Housing for Older Persons Act (HOPA), Pub.L. No. 104-76, § 2, 109 Stat. 787, which revised the 55 or older exemption.

Under the FHA, as amended by the FHAA and HOPA, housing qualifies for the 55 or older exemption ("the HOPA exemption") when it is "intended and operated for occupancy by persons 55 years of age or older" and three requirements are satisfied:

42 U.S.C. § 3607(b)(2)(C).3 It is the third of these criteria—the requirement that the community verify occupancy "by reliable surveys and affidavits"—that is at issue here. In 1999, HUD published final regulations implementing HOPA. See Implementation of the Housing for Older Persons Act of 1995, 64 Fed.Reg. 16,324, 16,329-16,332 (Apr. 2, 1999); 24 C.F.R. §§ 100.304-100.308. HUD adopted a regulation, 24 C.F.R. § 100.307, specifying the actions a community must take to satisfy the verification requirement mandated by 42 U.S.C. § 3607(b)(2)(C)(iii). Section 100.307 states:

24 C.F.R. § 100.307. The regulation requires communities to conduct surveys of residents at least once every two years to verify that at least 80 percent of its occupied units are occupied by at least one person 55 years of age or older. See id. § 100.307(a), (c). The surveys must verify the ages of residents by using reliable documents or affidavits. See id. § 100.307(d), (e), (g). Summaries of the surveys must be made available to the public upon request. See id. § 100.307(i). And the surveys themselves must be maintained and produced in any administrative or judicial proceeding in which the community asserts the 55 or older exemption as a defense to a charge of discrimination. See id. § 100.307(a), (h).4

The 1999 regulations also established a one-year transition period, permitting communities that did not satisfy the 80 percent occupancy requirement at the time the regulations were issued to claim the exemption by satisfying the intent and verification requirements, see 42 U.S.C. § 3607(b)(2)(C)(ii)-(iii), and reserving unoccupied units for residents 55 and older. See 24 C.F.R. § 100.305(e)(5). During the transition period, if a community demonstrated an intent to be housing for persons 55 years or older and complied with the verification requirement, it could reserve unoccupied units for occupancy by at least one person who was 55 years or older and not violate the FHA's prohibitions on discrimination on the basis of familial status. See id. The transition period ended on May 3, 2000. See id.; 64 Fed.Reg. at 16,324.5

The regulations did not address how an existing community could obtain exempt status after expiration of the transition period. HUD touched on that issue, however, in a March 2006 memorandum from Bryan Greene, HUD's Deputy Assistant Secretary for Enforcement and Programs, to HUD regional directors. Greene's memorandum ("HUD's 2006 policy guidance") explains that communities can obtain exempt status after the transition period by achieving compliance with each of the statutory and regulatory requirements, including the 80 percent occupancy requirement. Beyond the transition period, however, communities can no longer achieve compliance by reserving unoccupied units for older residents or otherwise discriminating on the basis of familial status. The guidance explains:

Memorandum, Conversion to Housing for Older Persons Under the Fair Housing Act and the Housing for Older Persons Act of 1995, at 2 (Mar. 6, 2006) (emphasis in original).

II.

Ryderwood is a residential community located in Cowlitz County, Washington. It currently consists of approximately 270 single-family homes. It was established in 1953 "as a community to be occupied by and for the use and benefit of persons who are bona fide recipients of a pension or retirement annuity." In 1975, the Ryderwood Improvement and Service Association (RISA), which serves a role comparable to a homeowners' association for the community's residents, adopted amended bylaws limiting ownership and residence in Ryderwood to persons age 55 or older. These 1975 rules state:

The plaintiffs are 54 residents of Ryderwood. They filed this action against RISA in July 2009, alleging that the age restrictions imposed by RISA violate the FHA and that RISA has never satisfied the requirements of the HOPA exemption. Second Am. Compl. ¶¶ 72-73.6 They sought nominal and punitive damages, attorney's fees and costs, declaratory relief and an injunction barring RISA from enforcing rules that discriminate against families with children. Id. ¶¶ 75, 81.

The parties filed cross-motions for partial summary judgment. The plaintiffs argued that RISA could not avail itself of the HOPA exemption because it failed to properly "convert" to exempt status. Relying on HUD's 2006 policy guidance, they argued that a community that did not achieve compliance with all of the requirements of the HOPA exemption by the end of the transition period could obtain the benefit of the exemption only by "converting" to exempt status. They argued that a community could permissibly "convert" to exempt status only by achieving compliance with the exemption's requirements without engaging in familial status discrimination. Here, the plaintiffs argued, RISA first attempted to "convert" to exempt status in 2006 or 2007, when it first sought to comply with the verification requirement in 42 U.S.C. § 3607(b)(2)(C)(iii) and 24 C.F.R. § 100.307. They argued that any attempt to convert to exempt status at that time was ineffective because, as RISA admits, RISA was then restricting ownership and residence in Ryderwood to persons age 55 or older. The plaintiffs argued that RISA never properly "converted" to exempt status and thus cannot claim the benefit of the exemption. They contended that, "because RISA has never successfully converted to HOPA compliance [by achieving compliance without engaging in discrimination], RISA's discriminatory conduct constitutes a violation of the FHA." Pls.' Mot. Partial Summ. J. 13; see also Pls' Reply Supp. Mot. Summ. J. 2 ("Plaintiffs assert RISA is not HOPA compliant presently because it wrongfully discriminated against families with children while attempting to convert to HOPA compliance.").

In its opposition to plaintiffs' motion, and its own motion for partial summary judgment, RISA argued that it was permitted to rely on the HOPA exemption so long as it established that it was in compliance with each of the exemption's requirements at the time the alleged discriminatory housing practice occurred, irrespective of whether it first achieved compliance with those requirements without discriminating. RISA contended that "a community is entitled to rely on the exemption if in compliance as of the date of the alleged act of discrimination." Defs.' Opp'n Pl.'s Mot. Partial Summ. J. 18.

RISA also argued that it has satisfied each of the three requirements of the HOPA exemption at all relevant times:

1. 80 Percent Occupancy. The FHA requires a community claiming the HOPA exemption to show that "at least 80 percent of the occupied units are occupied by at least one person who is 55 years of age or older." 42 U.S.C. § 3607(b)(2)(C)(i). RISA argued that it has satisfied this requirement through an age verification survey that it completed in September 2007. That survey found that there were 273 available total housing units in Ryderwood, that 25 of those units were either vacant or unverifiable and that 248 housing units were occupied by at least one person age 55 or older. Thus, according to RISA's survey, over 90 percent of the available units were occupied by persons 55 years of age or older on that date.

2. Policies and Procedures Demonstrating an Intent to Operate as a 55 or Older Community. The FHA also requires a community to show that "the housing facility or community publishes and adheres to policies and procedures that demonstrate the intent" to operate as a community for persons 55 or older. Id. § 3607(b)(2)(C)(ii). RISA argued that it has satisfied this requirement by enforcing age restrictions and posting signs throughout the community stating that residency is limited to those 55 and older.

3. Verification by Reliable Surveys and Affidavits. RISA also argued that it has satisfied the requirement for verifying occupancy "by reliable surveys and affidavits." Id. § 3607(b)(2)(C)(iii)(I). RISA contended that it completed a survey of all residents in September 2007. The survey entailed "a request for each resident to show they met the 55+ condition by providing a drivers license, birth certificate, passport, and/or a state identification card." Defs.' Mot. Partial Summ. J. 22.

RISA also argued that it satisfied the verification requirement before 2007 because, although no age verification surveys were conducted, it "engaged in less formalized processes that were equally effective." Id. RISA presented evidence that it maintained and "regularly updat[ed] an active rolodex that records each residence by address and the current identi[t]ies of each resident." DeBriae Summ. J. Decl. ¶ 18. The rolodex cards include notations of residents' dates of birth. RISA also maintained "a Ryderwood phone book, which lists all residents in Ryderwood." Id. ¶ 19.

Id. In addition, when properties in Ryderwood are sold, RISA asks title companies "to inform the buyers that they need to contact the RISA office and to sign a membership certificate." Id. ¶ 20.

The plaintiffs challenged the adequacy of RISA's September 2007 survey in their opposition to RISA's motion for partial summary judgment. They asserted a number of flaws in the survey, arguing that the survey therefore failed to satisfy the FHA's statutory and regulatory requirements.

III.

The district court granted partial summary judgment to the plaintiffs and denied RISA's motion for partial summary judgment. The court accorded deference to HUD's 2006 policy guidance under Auer v. Robbins, 519 U.S. 452, 461, 117 S.Ct. 905, 137 L.Ed.2d 79 (1997), which holds that judicial deference is owed to an agency's interpretation of its own regulations. The court agreed with the plaintiffs that the guidance bars a defendant from qualifying for the HOPA exemption unless the community first achieved compliance with the exemption's requirements without discriminating against families with children. The court ruled that "[t]he memo is clear that under the regulations, once the transition period ended in May of 2000, any existing community seeking to comply with the HOPA is required to cease discrimination during the period of gaining compliance." Order Granting Mot. Partial Summ. J. June 4, 2010, at 12-13. The court ruled that RISA could not claim the HOPA exemption because it continued to discriminate while attempting to comply with the verification requirements.

Id. at 13 (citation omitted). Having rejected RISA's HOPA defense, the court concluded that RISA's rules restricting sales of homes in Ryderwood violated the FHA. The court did not address the plaintiffs' alternative argument that RISA did not qualify for the HOPA exemption because the 2007 survey failed to satisfy the age verification requirements set out in § 3607(b)(2)(C)(iii) and 24 C.F.R. § 100.307. The district court subsequently granted the plaintiffs' motion for a preliminary injunction, ordering RISA to "immediately cease any and all enforcement of age restrictions on the sale, rental, or residency of homes in Ryderwood." Order Granting Prelim. Inj. Mot. Aug. 11, 2010, at 5.

RISA timely appealed the preliminary injunction order. The district court also certified its summary judgment order for interlocutory appeal, and we granted RISA permission to appeal. See 28 U.S.C. § 1292(b). We also granted RISA's motion for a stay of the injunction pending appeal and invited the Secretary of HUD to file an amicus brief. We are grateful to the Secretary for having done so.

STANDARD OF REVIEW

We review de novo a district court's grant or denial of a motion for partial summary judgment. See Aguilera v. Alaska Juris F/V, O.N. 569276, 535 F.3d 1007, 1009 (9th Cir.2008) (denial); Dare v. California, 191 F.3d 1167, 1171 (9th Cir. 1999) (grant). We review for an abuse of discretion the district court's grant of a preliminary injunction. See Nike, Inc. v. McCarthy, 379 F.3d 576, 580 (9th Cir. 2004).

We defer to HUD's reasonable interpretation of the FHA. See Meyer v. Holley, 537 U.S. 280, 287-88, 123 S.Ct. 824, 154 L.Ed.2d 753 (2003); Harris v. Itzhaki, 183 F.3d 1043, 1051-52 (9th Cir.1999). "[T]he agency is entitled to further deference when it adopts a reasonable interpretation of regulations it has put in force." Barrientos v. 1801-1825 Morton LLC, 583 F.3d 1197, 1214 (9th Cir.2009) (quoting Fed. Express Corp. v. Holowecki, 552 U.S. 389, 397, 128 S.Ct. 1147, 170 L.Ed.2d 10 (2008) (internal quotation marks omitted)). "[W]e accept the agency's position unless it is `plainly erroneous or inconsistent with the regulation.'" Fed. Express Corp., 552 U.S. at 397, 128 S.Ct. 1147 (quoting Auer, 519 U.S. at 461, 117 S.Ct. 905). "Further, an agency's litigation position in an amicus brief is entitled to deference if there is `no reason to suspect that the interpretation does not reflect the agency's fair and considered judgment on the matter.'" Barrientos, 583 F.3d at 1214 (quoting Auer, 519 U.S. at 462, 117 S.Ct. 905). Finally, HUD's "interpretive policy statements are at least `entitled to a measure of respect under the less deferential Skidmore standard.'" Id. (quoting Fed. Express Corp., 552 U.S. at 399, 128 S.Ct. 1147). In interpreting the HOPA exemption, we bear in mind that "[e]xemptions from the Fair Housing Act are to be construed narrowly, in recognition of the important goal of preventing housing discrimination." United States v. City of Hayward, 36 F.3d 832, 837 (9th Cir.1994) (quoting Massaro v. Mainlands Section 1 & 2 Civic Ass'n, 3 F.3d 1472, 1475 (11th Cir.1993) (internal quotation marks omitted)).

DISCUSSION

RISA does not dispute that it engages in conduct that, unless exempt, constitutes unlawful familial status discrimination under the FHA. RISA restricts ownership and residence in Ryderwood to persons who are 55 years of age or older, practices that would violate several provisions of the FHA. See 42 U.S.C. § 3604(a)-(d). The sole issue, therefore, is whether RISA is exempt from the FHA's prohibitions on familial status discrimination under one of the housing for older persons exemptions set out in § 3607(b). RISA relies exclusively on the 55 or older exemption ("the HOPA exemption"). See id. § 3607(b)(2)(C). As the HOPA exemption is an affirmative defense, RISA bears the burden of establishing that Ryderwood satisfies each of the HOPA requirements. See Massaro, 3 F.3d at 1475; Gibson v. Cnty. of Riverside, 181 F.Supp.2d 1057, 1076 (C.D.Cal.2002); 64 Fed.Reg. at 16,325. RISA must show that it satisfied the HOPA requirements at the time that the alleged discriminatory housing practice occurred.7

The district court concluded that RISA does not qualify for the HOPA exemption with respect to any time between the end of the transition period in May 2000 and the present. We agree in part and disagree in part with that conclusion. The court properly concluded that RISA did not qualify for the HOPA exemption between May 2000 and September 2007, when RISA completed its first HOPA verification survey, because during that time RISA did not verify by reliable surveys and affidavits—or through other adequate means—that at least 80 percent of its occupied units were occupied by at least one person who was 55 years of age or older. See 42 U.S.C. § 3607(b)(2)(C)(iii). The court erred, however, when it concluded that RISA was barred from availing itself of the exemption beginning in September 2007, when it completed the initial verification survey, merely because it had failed to "convert" to exempt status without engaging in familial status discrimination.

I. Compliance Between May 2000 and September 2007

To qualify for HOPA's affirmative defense, a community must satisfy all three statutory and regulatory requirements. See Hayward, 36 F.3d at 837; see also 42 U.S.C. § 3607(b); 24 C.F.R. §§ 100.304-100.307.8 Between May 2000 and September 2007, RISA did not satisfy one of these requirements—the obligation to verify by reliable surveys and affidavits that at least 80 percent of Ryderwood's occupied units were occupied by at least one person who was 55 years of age or older. See 42 U.S.C. § 3607(b)(2)(C)(iii); 24 C.F.R. § 100.307.

RISA did not perform verification surveys between 2000 and 2006. With respect to 2000-2004, RISA concedes that it did not conduct surveys. See Opening Brief 2 ("RISA does not dispute that in the years 2000-04, it failed to conduct a formal `HOPA survey' to verify Ryderwood residents' ages, as HOPA regulations provide . . . ."). With respect to 2005-2006, RISA contends that it did conduct a survey, but has declined to place evidence of the 2006 survey in the record, instead relying exclusively on the September 2007 survey to establish its compliance with HOPA. We construe RISA's actions as a concession that the 2006 survey does not satisfy HOPA.

RISA nonetheless argues that it satisfied the age verification requirement between 2000 and 2006 because, although it did not conduct adequate verification surveys during that period, it "engaged in less formal verification processes that were equally effective." Opening Br. 28. RISA describes these efforts as follows:

Id.

These verification efforts fall short of the statutory requirements. To satisfy HOPA's verification requirement, a community must verify the age of its residents at least once every two years; the verification must cover all housing units in the community; residents' ages must be verified using reliable documents; a record of the verification, including copies of the relevant documentation, must be maintained in the community's files; and the community must be able to produce that record in response to a complaint of discrimination. See 24 C.F.R. § 100.307(a)-(e). Whether considered individually or collectively, the verification efforts described by RISA— the rolodex cards and RISA membership forms—do not satisfy these criteria.

1. The Rolodex. RISA apparently maintains a rolodex card for each home in the Ryderwood community. Based on our review of the four sample cards RISA has included in the excerpts of record, we infer that each card contains a list of household residents and information about their dates of birth.

These cards do not satisfy HOPA, however. First, they provide current information on Ryderwood residents, rather than providing a record of verifications that should have been conducted biennially between 2000 and 2006. RISA cannot rely on current rolodex information to establish that it verified the ages of Ryderwood's residents in 2000, 2002, 2004 or 2006— especially when no claim has been made that any such verifications actually occurred. Second, although the cards include information about residents' ages, RISA does not contend that this information rests on reliable documentation, such as driver's licenses, birth certificates, passports and signed certifications, as § 100.307(d) requires.

2. RISA Membership Forms. RISA also argues that its membership forms satisfy the HOPA verification requirement between 2000 and 2006. RISA explains that it has continuously required Ryderwood homeowners to join its association. To become members, residents are required to complete and sign a membership form. Since 1996, that form has required residents to include information regarding their ages. RISA contends that the existence of these forms is adequate to establish that it verified Ryderwood's compliance with the occupancy requirement at all times between 2000 and 2006.

We disagree. Verifications, which must take place at least once every two years, occur at fixed points in time. To satisfy the requirement, a community must do more than collect some data over some period of time. It must collect complete data for all residences. The data must be current (as of the time of the verification). And the community must compile the data: the community must show that it actually used the data to verify that the community in fact satisfied HOPA's 80 percent occupancy requirement at the time of the verification. Here, we have no basis to conclude that the membership forms covered all residences or that they provided current information at any time between 2000 and 2006. See Brief of the Secretary of the U.S. Department of Housing and Urban Development as Amicus Curiae ("HUD Br.") 22 ("Requiring new residents to join RISA and purportedly attest to their age does not establish that all members or an occupant of all households have signed this verification, nor has RISA so claimed . . . . Notwithstanding the bylaws' requirement that homeowners be at least 55 years old, RISA membership forms dated from 1990-1992 did not specifically require that a resident report his or her age."). Furthermore, even if the membership forms contained complete and current information, at no time between 2000 and 2006 did RISA use the information to verify that the occupancy requirement was satisfied. We agree with the HUD Secretary that "[t]he mere possession of various records collected over the years . . ., without more, is inadequate to satisfy the verification obligation. A community must collate information from its files to assess whether, in fact, it has verifiable data of all current occupants and it satisfies the 80% occupancy requirement." Id. at 20-21. Here, RISA "has not shown that it has compiled a list of RISA members and compared [the membership] data with occupants for any given year to verify that the 80% occupancy requirement was met." Id. at 22. Merely requiring residents to fill out membership forms, "absent any compilation of data, is . . . insufficient to meet the verified survey requirement." Id.

We accordingly agree with HUD that "RISA's pre-2007 efforts fail to satisfy HOPA's age verification requirements." Id. In doing so, we do not disagree with RISA's contention that the HOPA verification requirement may be satisfied by means other than conducting a survey: HUD's regulations provide that a community may verify occupancy "through surveys or other means." 24 C.F.R. § 100.307(c) (emphasis added).9 The means employed, however, must satisfy the minimum criteria established by the statute and regulations. The efforts undertaken by RISA between 2000 and 2006 do not do so. (Nor were they designed to do so. See DeBriae R. 30(b)(6) Dep. 31:3-19, Feb. 12, 2010 (testifying that it was not until spring 2006 that RISA even decided to comply with the HOPA requirements).) The district court thus properly concluded that RISA does not qualify for the HOPA exemption between 2000 and 2006.

II. RISA's Compliance Since 2007

The district court concluded that, even assuming that RISA completed a valid verification survey in September 2007, it cannot qualify for the HOPA exemption because it neither achieved full compliance with HOPA's requirements during the transition period nor properly "converted" to exempt status after the transition period ended by achieving full compliance without discriminating against families with children.

A.

We agree with HUD that the district court erred. The HUD Secretary's amicus brief explains that

HUD Br. 12-13.

HUD's position is consistent with the FHA's plain text. Section 3607(b) provides that a community is exempt from the prohibitions on familial status discrimination when the three HOPA requirements are satisfied. See 42 U.S.C. § 3607(b)(2)(C) (providing that the FHA's familial status prohibitions do not apply to housing when "at least 80 percent of the occupied units are occupied by at least one person who is 55 years of age or older," that the "community publishes and adheres to policies and procedures" demonstrating the intent to operate as a HOPA community and that the "community complies with rules issued by [HUD] for verification of occupancy" (emphasis added)). Nothing in the statute suggests that a community's past actions preclude it from qualifying for the exemption based on current compliance.

The district court erred by relying on HUD's 2006 policy guidance to reach a different conclusion. The guidance addresses a situation not presented here— "how a community that had not reached the 80% occupancy threshold by the end of the transition period could convert to housing for older persons and take advantage of the HOPA exception." HUD Br. 24.

Id.

This conclusion does not reward RISA for having disregarded the verification requirement, as the plaintiffs contend. Assuming arguendo that the September 2007 survey satisfies the verification requirement, RISA became exempt from the FHA's prohibitions on familial status discrimination at that time, but RISA cannot claim the exemption for any prior period. See Hayward, 36 F.3d at 837 (housing must meet all three HOPA requirements to qualify for the exemption); HUD, Questions and Answers Concerning the Final Rule Implementing the Housing for Older Persons Act of 1995, at 13 ("If an individual files a complaint based on familial status and the housing community . . . claims the exemption as a defense, . . . [t]he community. . . has the burden of proving that it was in compliance with HOPA requirements on the date of occurrence of the alleged act or incident of discrimination." (emphasis added)). Current compliance with the verification requirement, in other words, will not shield a community from liability for discrimination occurring before compliance was achieved. And any person aggrieved by that pre-compliance discrimination has two years in which to bring suit. See 42 U.S.C. § 3613(a)(1)(A)("An aggrieved person may commence a civil action in an appropriate United States district court or State court not later than 2 years after the occurrence or the termination of an alleged discriminatory housing practice . . . ."). A community may not, therefore, disregard the verification requirement with impunity.

B.

The parties dispute whether RISA's September 2007 survey satisfies the statutory and regulatory criteria. The district court, which has not yet addressed that issue, should do so on remand.

CONCLUSION

We affirm in part and vacate in part the district court's grant of partial summary judgment to the plaintiffs. We vacate the preliminary injunction and remand for further proceedings. Each party shall bear its own costs on appeal.

AFFIRMED IN PART, VACATED IN PART and REMANDED.