Normally a support order is retroactive to the date of filing. If, however, there was a reason someone was precluded from filing for support, say for a physical or mental disability, the support order could be retroactive to the date they could have filed if they had been able. If a party conceals their income, the court could find that they are in contempt of an order that requires material changes to be reported in seven days and the court could retroactively modify the support to the date that they concealed their income. This also requires that the other party timely file once they learn of the misrepresentation. In these cases, a Court can retroactively adjust the amount of arrears on a support order. If there is a change income after a support order is entered that would materially affect the amount of support, it must be disclosed to the other side.