We reverse a Court of Appeals’ decision which denied the legal right of a father to offset social security disability payments against child support obligations pursuant to RCW 26.18.190(2) (1994).
Facts
Peggy and Dr. Dewayne Briscoe married in 1986. Twin children were born of the marriage the following year. In 1990 Dewayne injured his back and hands in a car accident and as a result discontinued his practice as an oral surgeon. Thereafter, each of his two children received $191 monthly federal social security disability benefits on his behalf.
*347In 1992 Peggy and Dewayne separated. Peggy instituted divorce proceedings. Dewayne and Peggy divided their property with Peggy receiving some $1.5 million in assets including their lakefront family home. Dewayne received assets valued at $1.8 million. Peggy was awarded custody of both children.
Dewayne agreed to pay $1,700 per month total child support to “facilitate settlement,” an amount which exceeded the $1,160 per month Dewayne would have been obligated to pay had the obligation been calculated according to the “Washington State Child Support Schedule,” without reference to the disability income. In early 1994 a decree of dissolution was entered finalizing the dissolution and incorporating the $1,700 per month child support obligation.
A few months later Dewayne asserted the right to offset the social security disability benefits paid to his children against his child support obligation. Accordingly he subtracted the amount of the disability payments, $382, from the $1,700 monthly child support payment.
Peggy filed a motion to force Dewayne to pay the full $1,700 without offset. The superior court granted Peggy’s motion and ordered Dewayne to pay back support. The Court of Appeals affirmed reasoning that because Dewayne had not included the social security payments to his children in his income he was not entitled to any offset. In re Marriage of Briscoe, 82 Wn. App. 529, 536, 919 P.2d 84 (1996). We granted review. 130 Wn.2d 1016, 928 P.2d 412 (1996).
RCW 26.18.190(2)
The relevant statute, RCW 26.18.190(2), effective on the date of the child support agreement and final decree of dissolution1 provides in full:
When the social security administration pays social security *348disability dependency benefits on behalf of or on account of the child or children of the disabled person, the amount of compensation paid for the children shall be treated for all purposes as if the disabled person paid the compensation toward satisfaction of the disabled person’s child support obligation.
The statute is unambiguous: Disability benefits paid directly to the children are in partial satisfaction of the disabled parent’s support obligation. See In re Marriage of Hughes, 69 Wn. App. 778, 782, 850 P.2d 555 (1993) (when the Legislature enacted RCW 26.18.190 it “specifically provided that such payments shall be offset” against the disabled parent’s child support obligations). Courts will not alter the plain meaning of statutory language through construction. State ex rel. T.B. v. CPC Fairfax Hosp., 129 Wn.2d 439, 451, 918 P.2d 497 (1996).
Statutory Law Incorporated
As a general rule parties to a marriage settlement are presumed to contract with reference to existing statutes, and statutes which directly bear upon the subject matter of the settlement are incorporated into and become part of the decree. Wagner v. Wagner, 95 Wn.2d 94, 98, 621 P.2d 1279 (1980). The parties, however, may exclude such relevant statutes from their agreement but to do so they must expressly declare their mutual intention to so exclude. Id. at 99. An express agreement to exclude the relevant statute must be a “clear manifestation of intent ... to make the general law inapplicable,” Id. at 99, and must be “ ‘directly and distinctly stated or expressed rather than implied or left to inference . . . .’ ” In re Marriage of Allen, 78 Wn. App. 672, 678, 898 P.2d 1390 (1995) (quoting In re Marriage of Main, 38 Wn. App. 351, 352, 684 P.2d 1381 (1984)). Failure to exclude results in automatic inclusion. In re Marriage of Williams, 115 Wn.2d 202, 209, 796 P.2d 421 (1990).
RCW 26.18.190(2) is therefore incorporated into the child support agreement unless the parties expressed a specific *349and manifestly clear intent to exclude its application. But these parties did not.2 There was certainly no express declaration of intent to exclude the statutory offset otherwise mandated by RCW 26.18.190(2) in the decree or incorporated agreement. Thus the statutory offset contained in RCW 26.18.190(2) applies to the Briscoe child support agreement and forms a part thereof. Accordingly $382 in disability benefits paid to the Briscoe children on Bewayne’s behalf must be treated as if Bewayne himself paid said amount “toward satisfaction of [his] child support obligation.” RCW 26.18.190(2). So long as Bewayne’s children receive $382 in social security disability dependency benefits on his behalf, his $1,700 monthly child support obligation is satisfied by payment of the $1,318 difference.
Value of Benefits Included as Income
Relying upon In re Marriage of Maples, 78 Wn. App. 696, 899 P.2d 1 (1995), the Court of Appeals concluded Bewayne should have included the amount of disability benefits within his income for purposes of determining his share of child support. Briscoe, 82 Wn. App. at 535-36. This is correct. However, we disagree that the proper result is denial of offset. The remedy under Maples for failure to include disability payments in one’s income is remand for a recalculation of the disabled parent’s income and recalculation of child support obligation, 78 Wn. App. at 707, not denial of the lawful entitlement to an offset. However, remand for recalculation is unnecessary in this case since the $1,700 monthly support offered by Bewayne in the child support agreement still exceeds his net support obligation even as modified by the inclusion of the disability payments in his income.
The Court of Appeals is reversed and the matter is *350remanded for further proceedings consistent with this opinion.3 Petitioner shall recover his costs on appeal.
Durham, C.J., and Smith, Johnson, Madsen, and Alexander, JJ., concur.
The statute was revised in 1995 to broaden the statute’s coverage to include retired and deceased persons. These changes are not material to our analysis.
On the contrary it appears the parties were aware that the social security benefits would offset. Indeed, prior to finalization of the child support agreement Peggy’s attorney wrote to Dewayne in a letter dated November 19, 1993: “I agree with you that we need to take the Social Security disability payments for the children into consideration when calculating the support.” Clerk’s Papers at 66-67.
Credit for overpayments, if any, may be considered on remand. See In re Marriage of Stem, 68 Wn. App. 922, 932-33, 846 P.2d 1387 (1993).