Cross appeals from two orders of the Family Court of Otsego County (Stiles, Support Mag.; Burns, J.), entered June 21, 2006 and July 31, 2006, which, inter alia, partially granted petitioner’s application, in a proceeding pursuant to Family Ct Act article 4, to direct respondent to pay child support and spousal maintenance.
The parties are married and the parents of three children (born in 1985, 1988 and 1989). They separated in 1999 and executed a written separation agreement in 2003. The agreement provided, among other things, that respondent would provide petitioner $100 per week in spousal maintenance and $250 per week in child support. In January 2006, petitioner commenced this proceeding seeking an upward modification of maintenance and child support. Respondent counterclaimed, seeking a reduction of his obligations under the parties’ agreement and an order requiring petitioner to apply for certain Medicare health coverage benefits. A fact-finding hearing was held and, as relevant here, a Support Magistrate dismissed that portion of petitioner’s application seeking additional spousal maintenance for lack of jurisdiction and denied respondent’s request for a downward modification of his obligations. Petitioner filed objections and respondent, in rebuttal, asserted that the “[o]rder of [the] Support Magistrate . . . should not be disturbed and the order should be sustained.” Family Court affirmed the Support Magistrate’s order in its entirety, and the parties now cross-*1082appeal from both the Support Magistrate’s order and the subsequent order of Family Court.
We affirm. With respect to petitioner’s arguments, we note that, on its face, the parties’ agreement is an attempt to permit petitioner to “seek[ ] additional maintenance [by] . . . filing in a court of appropriate jurisdiction for a modification of the present provisions concerning the payment of maintenance” (emphasis added). Consistent with the agreement and contrary to petitioner’s characterization of the petition as seeking a “de novo” determination of spousal maintenance, the petition expressly states that it is “an application to the [Family] Court for an upward modification of spousal support” (emphasis added), premised on the loss of certain Social Security benefits. It is well settled, however, that “Family Court is a court of limited jurisdiction which lacks the power to modify the terms of a separation agreement, as opposed to the terms of a divorce decree, and that this power cannot be conferred upon that court by agreement of the parties” (Kleila v Kleila, 50 NY2d 277, 282 [1980]; see Matter of Brescia v Fitts, 56 NY2d 132, 139 [1982]; cf. Standley v Standley, 83 AD2d 863, 864 [1981] [addressing the parties’ ability to seek modification in Supreme Court]). Moreover, there is no claim that any of the exceptions to this rule—i.e., that petitioner was likely to become a public charge, that the agreement was facially invalid or that respondent breached the agreement (see Family Ct Act § 463; Matter of Innis v Innis, 159 AD2d 307, 307-308 [1990]; Krochalis v Krochalis, 53 AD2d 1010, 1010-1011 [1976])—are present here.
In our view, the provision of the parties’ agreement directing that Family Court treat any applications by petitioner as “de novo” is not sufficient to alter the substance of the agreement, which is an improper attempt to confer subject matter jurisdiction upon Family Court. To the extent that Matter of SpilmanToll v Toll (209 AD2d 1015, 1016 [4th Dept 1994]) held that Family Court is a court of “competent jurisdiction” to modify a support agreement merely because the parties to the agreement have deemed it so, we decline to follow that case on the ground that it is inconsistent with the public policy as articulated by the Court of Appeals in Kleila v Kleila (50 NY2d at 282).
Finally, inasmuch as he failed to object to the Support Magistrate’s order before Family Court, respondent’s arguments are not properly before us (see Matter of Musarra v Musarra, 28 AD3d 668, 668-669 [2006]; Matter of Barker v Dorman, 292 AD2d 806, 806 [2002]; Matter of Ciampi v Sgueglia, 252 AD2d 755, 757-758 [1998]).
Spain and Lahtinen, JJ., concur.