N.J. Stat. § 40:56-37
Where the total amount of the assessments does not equal the cost of an improvement the difference between the cost of the improvement and the amount of the assessment shall be paid by the municipality and may be raised by taxation at large, or paid out of any funds of the municipality available for the purpose. It shall not be necessary to raise the whole amount of such difference in any one year but the same may be raised by equal installments to be fixed by the governing body. The entire amount to be raised by the municipality shall be levied before the date when bonds issued to secure the funds for the improvements fall due.
The financial officer of the municipality shall one month before the time for passing the annual tax budget report to the governing body the cost of each improvement completed during the year, the amount of the assessments levied therefor and the amount necessary to be levied by general taxation.
In municipalities having a comptroller or auditor the collecting officer immediately upon receipt of an assessment duplicate shall report the amount thereof to such comptroller or auditor.
N.J.S. § 40:56-37