*520OPINION OF THE COURT
Read, J.Section 207-a of the General Municipal Law mandates payment of the full amount of regular salary or wages to a paid firefighter “who is injured in the performance of his duties” or taken ill “as a result of the performance of his duties so as to necessitate medical or other lawful remedial treatment” (General Municipal Law § 207-a [1]). These payments continue until the disability ceases, or the disabled firefighter is granted a disability retirement. Payments stop if the firefighter either performs, or refuses to perform, light-duty work. The municipality is also liable for all medical treatment and hospital care necessitated by the illness or injury.
In their 1995-1998 collective bargaining agreement, the City of Poughkeepsie and the Poughkeepsie Professional Firefighters’ Association agreed to negotiate a procedure to implement section 207-a for the City’s firefighters. After negotiations proved fruitless, the Association concluded that impasse had been reached and petitioned the New York State Public Employment Relations Board (PERB or the Board) for compulsory interest arbitration. The City responded by filing an improper practice charge, alleging that the Association had violated Public Employees’ Fair Employment Act (Civil Service Law) § 209-a (2) (b), the Taylor Law. Specifically, the Association’s demands included proposals for de novo arbitral review to resolve disputes over a firefighter’s initial and continuing eligibility for General Municipal Law § 207-a benefits. The City insisted that these proposals were not mandatory subjects of bargaining.
PERB agreed. The Board viewed the Association’s proposals for de novo review as infringing upon the City’s exclusive statutory authority to make initial eligibility and termination decisions (see Matter of City of Poughkeepsie [Poughkeepsie Professional Firefighters’ Assn., Local 596, I.A.F.F., AFL-CIO-CLC], 33 PERB ¶ 3029 [2000]). The Association had “misinterpreted the import” (id. at 3078) oí Matter of City of Watertown (Water-town Police Benevolent Assn.) (30 PERB ¶ 3072 [1997]), where PERB decided that a demand for arbitration of disputes involving eligibility for the benefits conferred by General Municipal Law § 207-c—section 207-a’s counterpart for police officers— was a mandatory subject of negotiation. In Watertown, the union “merely requested” that any dispute over the City’s initial determination “be processed to arbitration pursuant to PERB’s Voluntary Dispute Resolution Procedure. There was no refer*521ence in the demand, either express or implied, that there would be a de novo review of the City’s initial determination” (33 PERB 1Í 3029, at 3079). Accordingly, the demand in Watertown was for “a substitute appeal procedure in order to avoid commencing an Article 78 proceeding,” and was found on this basis to be a mandatory subject of negotiations (id.).
After PERB’s decision in Poughkeepsie, the Association reworked its proposal and the parties resumed collective bargaining. This time around, the Association omitted “de novo” from the text of its proposed section 207-a procedures, which called for an arbitrator to review a firefighter’s eligibility for benefits, the termination of benefits and assignment to light duty. The proposal also recited that the City would have “exclusive authority to initially determine the applicant’s eligibility.”
Again, the parties were unable to negotiate an agreement, the Association petitioned PERB for compulsory interest arbitration and the City filed an improper practice charge in response. The City claimed that the modifications made by the Association to its previous demands were “cosmetic” only, and that its proposal still called for an arbitrator to make a decision on the merits of section 207-a claims. As a result, the demands “effectively wrest[ed] from the City the authority vested in it by GML § 207-a to make the initial determination,” and were non-mandatory subjects of collective bargaining.
Once again, PERB sided with the City. PERB concluded that the Association’s demands sought “review not of the City’s determinations of eligibility, termination of benefits and light duty but of the employees’ underlying claims,” and therefore “infringe[d] upon authority vested exclusively within municipalities by the statute” (Matter of City of Poughkeepsie [Poughkeepsie Professional Firefighters’ Assn., Local 596,1.A.F.F., AFL-CIO, CLC], 36 PERB ¶ 3014, at 3042 [2003]). Accordingly, the Association’s demands were nonmandatory subjects of negotiation, and its submission of them to interest arbitration was an improper practice in violation of section 209-a (2) (b) of the Taylor Law.
The Association commenced this CPLR article 78 proceeding, seeking annulment of PERB’s determination. Supreme Court granted the Association’s petition in its entirety. The Appellate Division subsequently reversed Supreme Court’s judgment on the law, and dismissed the petition. We now affirm.
*522General Municipal Law § 207-a authorizes municipalities to make initial determinations about a firefighter’s eligibility for benefits, and this authority is not a mandatory subject of collective bargaining (see Matter of Schenectady Police Benevolent Assn. v New York State Pub. Empl. Relations Bd., 85 NY2d 480 [1995]). A demand for a review procedure to contest a municipality’s initial determination is, however, mandatorily negotiable (see Matter of City of Watertown v State of N.Y. Pub. Empl. Relations Bd., 95 NY2d 73 [2000]). After examining the language in the Association’s proposal in light of these related, established principles, PERB concluded that the disputed demands afforded a firefighter de novo review—in effect, a fresh determination of the claim by an arbitrator—rather than arbitral review of the City’s initial determination, using a procedure and standard of review tailored by the parties.
This appeal presents no question of statutory interpretation. Instead, the issue is whether PERB decided the City’s improper practice charge based upon a reasonable reading of the Association’s proposed contract language. PERB, as the agency charged with interpreting the Civil Service Law, is accorded deference in matters falling within its area of expertise, including the resolution of improper practice charges (see Matter of County of Nassau [Nassau Community Coll.] v New York State Pub. Empl. Relations Bd., 76 NY2d 579, 585 [1990]). Because these matters are consigned to PERB’s discretion, we may not disturb its determination unless irrational (City of Watertown, 95 NY2d at 81).
Here, the proposed language calls for the arbitrator to resolve the firefighter’s claim, not review the City’s initial determination, and to decide all allegations and defenses, including assertions regarding timeliness; contemplates trial-type evidentiary hearings with witnesses; and even assigns burdens of proof according to the type of determination at issue. We therefore find no irrationality in PERB’s conclusion that the disputed demands set forth not a review procedure, but a redetermination procedure in derogation of the City’s nondelegable statutory right to make initial determinations.
Accordingly, the order of the Appellate Division should be affirmed, with costs.
Chief Judge Kaye and Judges G.B. Smith, Ciparick, Rosenblatt, Graffeo and R.S. Smith concur.
Order affirmed, with costs.