QUESTION
               You asked whether claimant R~ (Claimant), the surviving domestic partner of the number
                  holder, M~ (NH), is entitled to surviving spouse benefits and the Lump-Sum Death Payment
                  (LSDP).
               
               SHORT ANSWER
               Yes. Claimant and NH entered into a valid domestic partnership in California. Because
                  the NH died domiciled in Mexico, the agency applies District of Columbia law. Under
                  District of Columbia law, this domestic partnership conferred rights permitting Claimant
                  to inherit intestate from NH to the same extent as a surviving spouse. Accordingly,
                  the agency deems Claimant to be the NH’s surviving spouse for purposes of entitlement
                  to surviving spouse benefits and LSDP.
               
               SUMMARY OF EVIDENCE
               On January XX, 2009, Claimant and NH became registered domestic partners in the State
                  of California, as evidenced by the Certificate of Registered Domestic Partnership
                  issued by the State of California. Based on information provided by the C~, California
                  Field Office, the NH and Claimant resided inMexico, since February 2010. The NH died
                  in Mexico on April XX, 2016, according to a Report of Death of a U.S. Citizen issued
                  by the U.S. Consulate General, T~, Mexico.
               
               APPLICABLE LAW
               Federal Law
               To be entitled to survivor’s benefits under Title II of the Social Security Act (Act),
                  a claimant must establish that she or he is the widow or widower of an individual
                  who died fully insured.[1] See Social Security Act §§ 202(e) & (f), 216(c)(1) & (g)(1); 20 C.F.R. § 404.335. Similarly,
                  under the Act, upon the death of an insured individual, a LSDP may be paid to the insured’s widow or widower who was living in the same household
                  as the insured at the time of death. Social Security Act § 202(i); 20 C.F.R. § 404.391.
                  Under Section 216(h) of the Act, the agency will find a claimant to be the widow or
                  widower of an insured individual if the courts of the State in which the insured resided
                  at the time of his or her death would find that the claimant was validly married to
                  the insured when the death occurred.[2] Social Security Act § 216(h)(1)(A)(i). However, even if the claimant was not married
                  to the insured individual, the agency will deem the claimant to be the insured’s widow
                  or widower if, under the laws of the State where the insured had a permanent home,
                  the claimant would be able to inherit a surviving spouse’s share of the insured’s
                  personal property if he or she died without leaving a will. Social Security Act § 216(h)(1)(A)(ii);
                  20 C.F.R. § 404.345. Under such circumstances, the agency will treat the couple’s
                  relationship as a marital relationship. See id.
               In cases where the insured individual’s permanent home was not in one of the 50 States,
                  the Commonwealth of Puerto Rico, the Virgin Islands, Guam, or American Samoa, the
                  agency will look to the laws of the District of Columbia in order to determine whether
                  the claimant was the insured’s widow or widower. Social Security Act § 416(h)(1)(A);
                  20 C.F.R. § 404.345.
               
               In addition to establishing that she or he is the insured’s widow or widower, to recover
                  surviving spouse benefits, the claimant must show that she or he meets one of the
                  following conditions: (1) his or her relationship to the insured as wife or husband
                  lasted for at least nine months immediately before the insured died; (2) his or her
                  relationship to the insured as wife or husband did not last for at least 9 months
                  but another qualifying condition is satisfied[3] ; (3) he or she and the insured had a child together; or (4) in the month before
                  marrying the insured, he or she was entitled to or could have been entitled to certain
                  benefits or payments. See Social Security Act §§ 202(e) & (f); 20 C.F.R. § 404.335.
               
               District of Columbia Law
               Pursuant to the Health Care Benefits Expansion Act of 1992 (DC Law 9-114 (effective
                  June 11, 1992), codified at D.C. Code §§ 32-701 to 32-710), the District of Columbia
                  (District) recognizes domestic partnerships. To establish a domestic partnership in
                  the District, both persons must register as domestic partners by executing and filing
                  a declaration of domestic partnership with the Mayor. D.C. Code § 32-702(a). The declaration
                  must be signed by the domestic partners and affirm under penalty of perjury that each
                  person:
               
               (1) is at least 18 years old and competent to contract;
               (2) is the sole domestic partner of the other person;
               (3) is not married; and
               (4) is in a committed relationship with the other person.
               Id. In the District, each domestic partner has a right to inherit intestate from the
                  other domestic partner to the same extent as a surviving spouse. Id. §§ 19-301, 19-302.[4]
               Further, the District recognizes non-marital relationships established in accordance
                  with the laws of other jurisdictions that are “substantially similar” to domestic
                  partnerships in the District, where the term “substantially similar” is “broadly construe[d]”.
                  Id. § 32-702(i)(1). The District Code provides that the Mayor shall establish and maintain
                  a certified list of jurisdictions for which the District will recognize non-marital
                  relationships as domestic partnerships under District law. Id. However, if a jurisdiction is not included in the Mayor’s certified list, the District
                  Code directs that the non-marital relationship shall be recognized as a domestic partnership
                  in the District if, under the laws of that jurisdiction, the relationship has all
                  the rights and responsibilities of marriage. Id. § 32-702(i)(2). As discussed below, California is included in the Mayor’s certified
                  list.
               
               California Law
               To establish a domestic partnership in California, both persons must file a declaration
                  of domestic partnership with the Secretary of State, declaring that:
               
               (1) neither person is married or a member of another domestic partnership;
               (2) the two persons are not related by blood;
               (3) both persons are at least 18 years of age;
               (4) both persons are members of the same sex; and
               (5) both persons are capable of consenting to the domestic partnership.
               See Cal. Fam. Code §§ 297(b), 298.5(a).[5] The Secretary of State registers the declaration of domestic partnership and issues
                  a Certificate of Registered Domestic Partnership to the couple. Id. § 298.5(b).
               
               In California, registered domestic partners have the same rights and responsibilities
                  as spouses in a marital relationship. Id. § 297.5(a). Further, surviving registered domestic partners have the same rights
                  and responsibilities as surviving spouses in a marital relationship. Id. § 297.5(c); see Cal. Prob. Code § 37.
               
               ANALYSIS
               Claimant and the NH entered into a registered domestic partnership in California on
                  January -XX, 2009, approximately seven years before the NH’s death. The relationship
                  therefore exceeds the nine-month duration requirement for surviving spouse benefits.[6] See 20 C.F.R. § 404.335(a)(1); Program Operations Manual System (POMS) GN 00210.004.
               
               Claimant was residing with the NH in Mexico at the time of NH’s death. Accordingly,
                  to determine Claimant’s entitlement to surviving spouse benefits, the agency will
                  look to District of Columbia law. If, under District laws, Claimant would be able
                  to inherit intestate from the NH to the same extent as a surviving spouse, then the
                  agency will deem Claimant to be the NH’s widower. See Social Security Act § 216(h)(1)(A)(ii); 20 C.F.R. § 404.345.
               
               The District will recognize a non-marital relationship formed in another jurisdiction
                  – and treat it the same as a domestic partnership in the District – if: (1) the jurisdiction
                  is included in the Mayor’s certified list of jurisdictions for which the District
                  recognizes non-marital relationships; or (2) under the laws of the other jurisdiction,
                  the non-marital relationship provides all the rights and responsibilities of marriage
                  in that jurisdiction. D.C. Code § 32-702(i)(1)-(2).
               
               Both alternatives are satisfied here.
               First, California is included on the Mayor’s list as a jurisdiction for which the
                  District will recognize non-martial relationships as domestic partnerships in the
                  District. See D.C. Mun. Regs. tit. 29, § 8001.6(a) (providing that domestic partnerships registered
                  in California pursuant to California Family Code § 297 et. seq. are recognized as domestic partnerships in the District).
               
               Second, the State of California bestows the same rights and responsibilities on registered
                  domestic partners as spouses receive in a marriage. Cal. Fam. Code § 297.5(a), (c).
               
               Accordingly, under either alternative, the District of Columbia will recognize the
                  California domestic partnership between Claimant and the NH as a domestic partnership
                  in the District. See D.C. Code § 32-702(i)(1) & (2). In the District, registered domestic partners receive
                  the same rights as married couples for relevant purposes, including the right to inherit
                  intestate. See D.C. Code § 19-302; see also POMS GN 00210.004 (noting District domestic partnerships provide for “spousal inheritance
                  rights”). The Claimant could therefore inherit intestate from the NH under District
                  laws, and the agency will deem him to be the NH’s surviving spouse. See Social Security Act § 216(h)(1)(A)(ii); 20 C.F.R. § 404.345.
               
               In addition, because Claimant was living in the same household as the NH at the time
                  of his death, the agency will deem Claimant to be the NH’s surviving spouse entitled
                  to the LSDP. Social Security Act § 202(i); 20 C.F.R. § 404.391.
               
               CONCLUSION
               Because the NH was domiciled in Mexico at the time of death, the agency uses District
                  of Columbia law to determine the status of Claimant’s relationship to the NH. Under
                  District of Columbia law, the California domestic partnership of Claimant and the
                  NH would be recognized as a domestic partnership with the same rights as surviving
                  spouses, for relevant purposes, including the right to inherit intestate. As a result,
                  Claimant could inherit intestate from the NH to the same extent as a surviving spouse
                  under District of Columbia law. Accordingly, we believe the agency can entitle Claimant
                  to surviving spouse benefits and LSDP.