WIGGINS, J.
¶ 1 Linda Darkenwald appeals from the Washington Employment Security Department's (Department) denial of her claim for unemployment benefits. We must decide whether a desire to work only part time constitutes a good cause reason for leaving work, thus permitting an individual who leaves work for that reason to collect unemployment benefits. Darkenwald claims that her employer's request that she increase her working hours to three days per week gave her good cause to leave work because she wanted to continue working only two days a week. She relies on a statute that does not apply to her and would not give her good cause to leave work even if it were applicable. The Employment Security Act (Act), Title 50 RCW, lists good-cause reasons for voluntarily leaving work and states that this list is exclusive. A desire to perform only part-time work is not a good cause under the Act, and the part-time worker provisions do not apply.
¶ 2 Darkenwald worked as a dental hygienist in the office of Dr. Gordon Yamaguchi from 1985 to 2010. Initially, Darkenwald worked one day a week, but she increased this to two days a week and then four days a week. In 1998, she suffered a neck and back injury. Darkenwald received worker's compensation benefits after the Department of Labor and Industries found that she had a permanent impairment. Despite her injury, Darkenwald continued to work three to four days a week until 2006. From that point on, Darkenwald worked only on Mondays and Wednesdays, for a total of 14 to 17 hours per week. Dr. Yamaguchi asserts that Darkenwald reduced her hours in order to spend more time with her family.
¶ 3 In 2010, Dr. Yamaguchi added another dentist to his practice. Dr. Yamaguchi met with Darkenwald and asked her to return to working three days a week; specifically, he asked her to work Fridays in addition to Mondays and Wednesdays. In the alternative, he offered her a position as an on-call or substitute hygienist.
¶ 4 Eight days after her last day at Dr. Yamaguchi's office, Darkenwald filed a claim for unemployment benefits with the Department, asserting that she had been fired. Her initial application for benefits listed "wanted me to work more days" as the reason she was fired. The application did not mention her disability. After reviewing Dr. Yamaguchi's response, the Department denied Darkenwald's claim, stating that she had not been discharged but rather had "quit for personal reasons" and had "not established good cause" for quitting.
¶ 5 Darkenwald appealed the denial of her claim to an administrative law judge (ALJ) with the Department. The ALJ concluded
¶ 6 Darkenwald appealed to the Thurston County Superior Court, which reversed the commissioner's decision and directed the Department to grant Darkenwald unemployment benefits. The Superior Court rejected the commissioner's findings that Darkenwald had voluntarily quit and "that Darkenwald refused or was not interested in working on Fridays." Instead, the Superior Court concluded that Darkenwald's disability prevented her from working more than two days a week and that Dr. Yamaguchi's request for Darkenwald to work three days a week made him "the moving or initiating party leading to Darkenwald's termination."
¶ 7 The Court of Appeals reversed the Superior Court and reinstated the commissioner's denial of benefits. Darkenwald v. Emp't Sec. Dep't, 182 Wn.App. 157, 179, 328 P.3d 977 (2014). The Court of Appeals held that substantial evidence supported the commissioner's findings that Darkenwald had voluntarily quit, that Darkenwald's disability was not the primary reason she quit, and that her disability did not make it necessary for her to quit. Id. at 172-75, 328 P.3d 977. The appellate court held that the protections that the Act accords to unemployed part-time workers did not establish good cause for Darkenwald to quit, reasoning that a contrary holding would be contrary to the legislative intent that the list of "good causes" for quitting that the Act is exclusive. Id. at 177-79, 328 P.3d 977.
¶ 8 We sit in the same position as the Superior Court and thus do not give deference to the rulings of the Superior Court or Court of Appeals. Verizon Nw., Inc. v. Emp't Sec. Dep't, 164 Wn.2d 909, 915, 194 P.3d 255 (2008). Under the Washington Administrative Procedure Act, chapter 34.05 RCW, we review the decision of the commissioner rather than the underlying decision of the ALJ, except to the extent that the commissioner adopts the ALJ's findings. Verizon Nw., 164 Wash.2d at 915, 194 P.3d 255.
¶ 9 As the party challenging the commissioner's decision, Darkenwald bears the burden of demonstrating the invalidity of the Department's action. RCW 34.05.570(1)(a). Our task is to determine whether the Department erroneously interpreted or applied the law, whether its decision is supported by substantial evidence, and whether the decision is arbitrary and capricious. RCW 34.05.570(3)(d), (e), (i). We review administrative findings of fact for substantial evidence, and unchallenged findings are treated as verities on appeal. Smith v. Emp't Sec. Dep't, 155 Wn.App. 24, 32-33, 226 P.3d 263 (2010). We review issues of law de novo. Quadrant Corp. v. Growth Mgmt. Hr'gs Bd., 154 Wn.2d 224, 233, 110 P.3d 1132 (2005).
¶ 10 On matters of statutory interpretation, our "fundamental objective is to ascertain and carry out the Legislature's intent." Dep't of Ecology v. Campbell & Gwinn, LLC, 146 Wn.2d 1, 9, 43 P.3d 4 (2002). "[I]f the statute's meaning is plain on its face, then the court must give effect to that plain meaning as an expression of legislative intent." Id. at 9-10, 43 P.3d 4. When determining a statute's plain meaning, we consider "the ordinary meaning of words, basic rules of grammar, and the statutory context to conclude what the legislature has provided for in the statute and related statutes." In re Forfeiture of One 1970 Chevrolet Chevelle, 166 Wn.2d 834, 838-39, 215 P.3d 166 (2009). We consider other matters, including legislative history, if "the statute remains susceptible to more than one reasonable meaning" after completing this plain-meaning analysis. Campbell & Gwinn, 146 Wash.2d at 12, 43 P.3d 4.
¶ 11 RCW 50.20.050 disqualifies a worker from receiving unemployment benefits if the worker "left work voluntarily without good cause." RCW 50.20.050(2)(a). The statute further provides that "[g]ood cause reasons to leave work are limited to reasons listed in (b) of this subsection." Id. Consequently, a worker who voluntarily leaves work must satisfy the requirements of 1 of the 11 causes enumerated in RCW 50.20.050(2)(b) in order to demonstrate good cause.
¶ 12 The ALJ and the commissioner determined that Darkenwald quit—i.e., that she voluntarily left work—rather than being discharged. Darkenwald failed to meaningfully challenge this conclusion in her petition for review and instead argued that she is entitled to benefits regardless of whether the termination of her employment is characterized as a "quit" or a discharge.
¶ 13 Because Darkenwald left work voluntarily, RCW 50.20.050(2)(a) disqualifies her from receiving benefits unless she satisfies one of that statute's enumerated "[g]ood cause reasons" for leaving work. Darkenwald asserts that both her disability and her desire to remain a part-time worker provided her with good cause to leave her employment with Dr. Yamaguchi. Both of these arguments fail.
¶ 14 Disability constitutes good cause for voluntarily leaving work under certain circumstances:
RCW 50.20.050(2).
¶ 15 The associated regulations
¶ 16 Darkenwald failed to establish that she exhausted all reasonable alternatives under WAC 192-150-055(1)(c) and fails to challenge the Court of Appeals' conclusion that her disability was not the primary reason she left work as required by WAC 192-150-055(1)(a). Consequently, her disability did not constitute good cause.
¶ 17 WAC 192-150-055(1)(c)(i) requires a worker to satisfy the notification-to-employer requirements of WAC 192-150-060 in order to demonstrate that she "exhaust[ed] all reasonable alternatives prior to leaving work." Under WAC 192-150-060(1), a worker who leaves work because of a disability must first notify the employer about the disability and "any known restrictions on the type or hours of work [the worker] may perform." Any such "restrictions on the type or hours of work [the worker] may perform must be supported by a physician's statement. . . ." WAC 192-150-060(2). As the Court of Appeals noted, see Darkenwald, 182 Wash.App. at 175, 328 P.3d 977, Darkenwald never presented such a physician's statement to Dr. Yamaguchi; Darkenwald does not dispute this in her petition for review or supplemental brief. Because she never provided a physician's statement prior to quitting, Darkenwald failed to "exhaust all reasonable alternatives" under WAC 192-150-055(1)(c)(i).
¶ 18 The Court of Appeals provided an alternative rationale for rejecting Darkenwald's disability argument, holding that Darkenwald failed to establish that her disability was the primary reason she left work, as required by WAC 192-150-055(1)(a). Darkenwald, 182 Wash.App. at 173-74. At the beginning of her petition for review, Darkenwald states that she seeks review of the Court of Appeals' conclusion that her disability was not the primary reason she quit. But Darkenwald never again mentions the "primary reason" component of the Court of Appeals' decision in either her petition for review or her supplemental brief. "[I]ssues not supported by argument and citation to authority will not be considered on appeal." State v. Farmer, 116 Wn.2d 414, 432, 805 P.2d 200, 812 P.2d 858 (1991). On the "primary reason" requirement of WAC 192-150-055(1)(a), Darkenwald has supplied neither argument nor citation to authority. Because Darkenwald has failed to meaningfully challenge that conclusion, we conclude, as did the Court of Appeals, that Darkenwald's disability was not the primary reason she left work.
¶ 19 For these reasons, Darkenwald has failed to establish that her disability provided her with good cause to leave work.
¶ 20 We also reject Darkenwald's argument that her desire to remain a part-time-only worker provided her with good cause to
¶ 21 RCW 50.20.050(2)(a) states that its enumerated list of "good causes" is exclusive. That list does not include a provision covering employees who wish to limit their work hours, nor does it include a provision covering an employer's demand that an employee work more hours. The absence of part-time worker status from the list thus suffices to defeat Darkenwald's argument that her desire to work only part time provided her with good cause.
¶ 22 Our inquiry ordinarily would end there. Darkenwald asserts, however, that a separate statute, RCW 50.20.119, creates an additional category of good cause that protects part-time workers who reject an offer of full-time employment. RCW 50.20.119(1) provides:
¶ 23 Darkenwald's argument incorrectly assumes that the above-quoted statute conflicts with RCW 50.20.050(2)(a)'s statement that the enumerated list of good causes is exclusive.
¶ 24 RCW 50.20.010(1)(c) requires a person who has filed a benefits claim to actively seek and accept "any suitable work" in order to retain eligibility for unemployment benefits. RCW 50.20.119 sets forth a limited exception to that rule: it excuses a claimant who is a "part-time worker" from searching for or accepting offers of full-time employment, even if the full-time employment would otherwise be "suitable." RCW 50.20.119(1). RCW 50.20.119 thus bars the Department from denying a part-time worker benefits simply because that worker failed to "active[ly] search for," "apply for," or "accept" full-time work. Id. Under the Act, a currently employed person need not "search for," "apply for," or "accept" employment in order to obtain unemployment benefits. Those obligations do attach, however, to already-unemployed individuals who have filed a claim for benefits—as the three statutes cited in RCW 50.20.119's text demonstrate.
¶ 25 Because the plain meaning of RCW 50.20.050(2) and RCW 50.20.119 are not ambiguous, we need not consider secondary considerations such as legislative history. See Campbell & Gwinn, 146 Wash.2d at 12, 43 P.3d 4. We note, however, that the legislative history behind RCW 50.20.050's exclusivity provision cuts against Darkenwald's proposed construction. Darkenwald's construction hinges on the assumption that RCW 50.20.050's list of causes is not exclusive and is augmented by RCW 50.20.119. The legislative history demonstrates that the legislature rejected reading such additional causes into the list. As noted supra note 7, the legislature added the exclusivity provision to RCW 50.20.050 in 2009, six years after the enactment of RCW 50.20.119. LAWS OF 2009, ch. 493, § 3. The legislature could have incorporated part-time worker protections into RCW 50.20.050 at that time, but it chose not to do so.
¶ 26 Moreover, the exclusivity provision appears to have been added in response to our 2008 opinion in Spain v. Employment Security Department, in which we held that the statute's list of good causes was not "exhaustive." 164 Wn.2d 252, 254-55, 185 P.3d 1188 (2008). The legislature amended RCW 50.20.050 to add the exclusivity provision just eleven months later. See LAWS OF 2009, ch. 493, § 3. The bill report addressing the amendment specifically cited Spain's nonexclusivity holding in its background section. FINAL B. REP. ON SECOND SUBSTITUTE S.B. 5963, at 2, 61st Leg., Reg. Sess. (Wash. 2009). "`[A] change in legislative intent is presumed when a material change is made in a statute.'" Davis v. Dep't of Licensing, 137 Wn.2d 957, 967, 977 P.2d 554 (1999) (quoting Rhoad v. McLean Trucking Co., 102 Wn.2d 422, 427, 686 P.2d 483 (1984)). Our decision in Spain was in keeping with a remedial reading of the statute; had the legislature believed such a construction appropriate for RCW 50.20.050, it could simply have left the statute as it was and allowed Spain to remain controlling law. Its decision to amend the statute less than one year later strongly suggests that the legislature did not believe the usual rules of remedial construction can be used to expand the list of good causes to leave work.
¶ 27 Darkenwald left her position at Dr. Yamaguchi's office without "good cause," as the Employment Security Act defines that term. We therefore affirm the Court of Appeals' decision and uphold the commissioner's determination that Darkenwald is not entitled to unemployment benefits.
WE CONCUR. MADSEN, C.J., JOHNSON, OWENS, FAIRHURST, STEPHENS, WIGGINS, GONZÁLEZ, GORDON McCLOUD, and YU, JJ.