Property Taxes and Assessments Division

Frequently Asked Questions


Proposition 13, approved by voters on June 6, 1978, established laws governing the valuation of properties in California for purposes of property taxation. It also set a county general tax rate limit of no more than one percent (1%) of the assessed value of the property. Property is re-assessed to its full cash value when acquired through a change of ownership or by new construction. There are exceptions to the valuation at the change of ownership. Each year thereafter, the taxable value of the property may increase by the rate of inflation (the change in market value) or by two percent (2%), whichever is less. Proposition 13 is under Article 13A of the Constitution of the State of California.

Proposition 8 allows the County Assessor to temporarily lower an assessment (the valuation of a property) when the market value on January 1 is less than the factored base year value for that year. Each case is reviewed individually upon request of the property owner. Whenever such relief is provided, the County Assessor is obligated to annually review the assessed value and adjust the assessment up or down to the market value, but never higher than the factored base year value.

The County levies an ad valorem property tax rate which equals one percent (1%) plus an additional rate for the amount needed to make payments for the principal and interest on general obligation bonds or other indebtedness approved by the voters. The tax rate is per every $100 of the assessed value.

Your property tax bill is comprised of taxes and special assessments and is a lien on your property. Taxes consist of a 1% general levy plus voter approved debt plus any applicable special assessments. Taxes and assessments are specifically identified on your tax bill and are distributed as stated on your bill, with the exception of the 1% general levy (which was established with Proposition 13). See chart on Property Tax Division page for Property Tax Distribution on a countywide basis.

In 1979, Assembly Bill 8 (AB 8) was adopted to provide procedures for counties to allocate property taxes. The basic premise of AB 8 allocates to each taxing jurisdiction the amount it received in the prior year, plus the change that has occurred in the current year within its boundaries. The revenue allocation of the countywide 1% property tax levy is calculated pursuant to Revenue and Taxation Code section 96.5.

Under the AB 8 method, the 1979/80 base amount for each local agency within a county was calculated based on the property tax allocated pursuant to Government Code section 26912 for 1978/79 and adjusted for the 1979/80 assessed value growth. The property tax allocation percentage for each agency within a Tax Rate Area (TRA) was then established. These percentages are to be recomputed only when certain activities occur such as TRA consolidation, creation of the unitary roll pursuant to Revenue and Taxation Code section 100, and boundary changes affecting specific TRAs, such as annexations, detachments, dissolution of districts, formation of new districts, city incorporations.

Special assessments (also referred to as direct assessments or direct charges) are non-ad valorem based charges levied on a per parcel basis and may differ from parcel to parcel. These charges may be for a variety of items; such as, charges for services, improvement district charges, 1915 Act bonds, Mello-Roos community facilities district charges, other voter-approved special taxes, special benefit assessment district charges, or fees.

It is the responsibility of the taxing agency or special district to calculate the amount of special assessment to charge each parcel. It is the role of the County Auditor-Controller’s Property Tax Division to place these tax amounts on the parcel’s tax bill and in turn distribute the tax revenue collected to the proper agency. Approximately 248,500 special assessment direct charges from more than 228 different districts and agencies are placed on the secured tax roll each year. For information on how to place a special assessment on a tax bill, please call our office at (209) 525-6597.

Special Assessments and their corresponding amounts may change with each roll year. For information regarding the direct assessment calculation, contact the district, agency, or city responsible for the assessment. The contact information for each agency is listed next to the charge by that agency on your tax bill.

State law requires the County Assessor’s Office to reappraise real property upon a change in ownership or completion of new construction. The Assessor’s Office must issue a supplemental assessment, which reflects the difference between the prior assessed value and the new assessed value. The supplemental assessment will be prorated from the date of the new assessed value through the remainder of the fiscal year; which ends June 30.

An increase in assessed value (when the new assessment is greater than the prior assessment) will result in a supplemental tax bill. The supplemental bill will be issued based on the change in value and is prorated over the remainder of the tax year. Due dates for supplemental tax bills depend on when the bill is mailed. All supplemental tax bills are in addition to the annual tax bill.

In some cases, two (2) supplemental bills may be issued. This occurs when the property changes ownership, or is otherwise re-assessed, after the January 1 lien date. The Assessor’s Office assigns a property value January 1st of every year for the following tax year (tax year is July – June).

Example:
A property is assessed at $100 on Jan 1, 2011 for the 2011-2012 tax year. The annual tax bill for the 2011-2012 year is based on a $100 value.

The same property is assessed at $102 on January 1, 2012 for the 2012-2013 tax year. The annual tax bill for the 2012-2013 year is based on a $102 value.

The same property is sold on March 1, 2012 for $110. This results in 2 supplemental bills.

One (1) bill will be issued based on a $10 value prorated over the remainder of the 2011-2012 tax year [$100 prior value – 110 new value = $10 supplemental bill value; for the period of March 1, 2012 - June 30, 2012].

A second (2nd) bill will be issued based on an $8 value covering the entire 2012-2013 tax year [$102 prior value – 110 new value = $8 supplemental bill value; for the period of Jul 1, 2012 – June 30, 2013].

In some cases, a property changes ownership before a secured or unsecured supplemental bill is issued for a prior change of ownership or completion of new construction. This will occur if you purchase and then sell property within a short period of time. The supplemental tax bill you receive should cover only those months during which you owned the property, and the new owner should receive a separate supplemental tax bill. Because of the large number of parcels and property transfers in Stanislaus County, there may be delays in placing new assessments on the roll.

A Value Notice is mailed by the Assessor approximately 30 days before the Supplemental bill. This notice details the value on which your supplemental tax bill was calculated.

State law requires the County Assessor’s Office to reappraise real property upon a change in ownership or completion of new construction. The Assessor’s Office must issue a supplemental assessment, which reflects the difference between the prior assessed value and the new assessed value. The supplemental assessment will be prorated from the date of the new assessed value through the remainder of the fiscal year; which ends June 30.

A decrease in assessed value (when the new assessment is less than the prior assessment) will result in a negative supplemental assessment – in other words, a supplemental refund. These refunds do not cause a change to your current annual tax bill, and the annual tax bill must be paid timely to avoid penalties.

In some cases, a property changes ownership before a secured or unsecured supplemental bill is issued for a prior change of ownership or completion of new construction. This will occur if you purchase and then sell property within a short period of time. The supplemental tax bill you receive should cover only those months during which you owned the property, and the new owner should receive a separate supplemental tax bill. Because of the large number of parcels and property transfers in Stanislaus County, there may be delays in placing new assessments on the roll.

A Value Notice is mailed by the Assessor approximately 30 days before the supplemental refund. This notice details the value on which your supplemental tax refund will be calculated.

If the change in ownership occurs or the new construction is completed on or after January 1, but on or before June 30, then there will be two supplemental assessments. The first supplemental assessment will be the difference between the new assessed value and the taxable value on the tax roll in existence for these dates. The second supplemental assessment will be the difference between the new assessed value and the taxable value on the next year’s tax roll. Refer to the example under "What is a supplemental tax bill?"

  • Secured Taxes = (Net Assessed Value x Tax Rate) + Special Assessments
  • Unsecured Taxes = (Net Assessed Value x Prior Year Secured Tax Rate) + Special Assessments
  • Supplemental Taxes = Net Assessed Value Difference x Tax Rate x Proration Period
    • In accordance with Revenue and Taxation Code section 75.41, the proration period is from the beginning of the month following the date on which the change of ownership occurred or the date of new construction to the end of the fiscal year on June 30.

A Mello-Roos direct levy is a special assessment imposed on those real property owners within a Community Facilities District. The district has chosen to seek public financing through the sale of bonds for the purpose of financing certain public improvements and services as outlined in the "Mello-Roos Community Facilities Act of 1982." The special assessment you pay is used to make the payments of principal and interest on the bonds. The special assessment will stay in effect until the principal and interest on the bonds are paid off along with any reasonable administrative costs incurred.

Services and facilities may include: police protection, fire protection, ambulance and paramedic services, recreation program services, libraries, library services, parks, parkway facilities, open space facilities, the operation and maintenance of parks, parkways and open space, museums, recreation facilities, child care facilities, cultural facilities, flood and storm protection, services for the removal of any threatening hazardous substance, elementary and secondary school sites and structures, natural gas pipeline facilities, telephone lines, facilities to transmit and distribute electrical energy, cable television lines, and others.

If the annual property tax bill includes a Mello-Roos special assessment and it is not paid in full by June 30, the property may be subject to the accelerated judicial foreclosure process. After June 30, those special assessments subject to the accelerated judicial foreclosure are removed from the unpaid tax bill and the Districts are responsible for collection enforcement.

Mello-Roos special assessments are levied on the tax bill on behalf of the Mello-Roos District and are not levied by the Assessor, Auditor-Controller or Tax Collector. For information or disclosure of a Mello-Roos special assessment levied against property, please contact the Mello- Roos District directly.The contact information for each district is listed next to the charge by that district on your tax bill.

A 1915 Act bond direct levy is a special assessment imposed on those real property owners within a development area. 1915 Act bonds are for public financing usually for improvements, such as streets, curbs, gutters and underground sewer and water infrastructure that generally enhance land value and give land utility. When a developer finances such improvements through a 1915 Act bond, developers pass on the debt to each home buyer as an assessment bond obligation specific to the buyer’s lot.

If the annual property tax bill includes a 1915 Act bond and it is not paid in full by June 30, the property may be subject to the accelerated judicial foreclosure process. After June 30, those special assessments subject to the accelerated judicial foreclosure are removed from the unpaid tax bill and the districts are responsible for collection enforcement.

1915 Act bonds are levied on the tax bill on behalf of the 1915 District and are not levied by the Assessor, Auditor-Controller or Tax Collector. For any information or disclosure of a 1915 Act bond levied against property, please contact the 1915 District directly. The contact information for each district is listed next to the charge by that district on your tax bill.

Refunds are normally processed within 30 days of the date when the Assessor certifies the reduction of assessment to the Auditor-Controller’s Office. If you are due a refund, you should first contact the Assessor’s Office at (209) 525-6461 to verify that the value reduction has been certified and the date of that certification. To check on the status of a refund for an Assessor certified value reduction, contact the Property Taxes & Assessments Division of the Auditor-Controller’s Office at (209) 525-6597.

Yes. You should pay the property tax bills you received. Penalties may not be forgiven because you were waiting for a revised bill. So, until you receive a revised bill, pay the tax bill you have. If this results in a net overpayment, a refund will be sent to you.

ERAF is a mechanism, enacted in July of 1992 by the State Legislature to shift local tax revenues from cities, counties, and special districts to a State controlled Education Revenue Augmentation Fund. The State uses this fund to reduce its obligation to the schools. ERAF funds have been used by the State to help school and community college districts meet minimum funding requirements.