Section 425-A. Abatement of county taxes in special assessing units

1.
  Local option. The local legislative body of a county that is  a  special
  assessing  unit  may  provide  by local law for the partial abatement of
  county taxes pursuant to this section. Such  abatement  shall  apply  to
  assessment  rolls  beginning with the roll finally completed in the year
  two thousand two, and continuing through and including the roll  finally
  completed  in  the  year  two  thousand fifteen unless such local law is
  sooner repealed.
    2. Eligible property. The property of a senior citizen that  qualifies
  for  and receives the enhanced exemption pursuant to subdivision four of
  section four hundred twenty-five of this  title  shall  be  eligible  to
  receive the abatement provided by this section.
    3.  Procedure.  No  separate  application  shall  be  required for the
  abatement. The assessor of such special assessing unit shall compute and
  apply the  abatement  when  extending  the  tax  on  eligible  property.
  Eligibility  for such abatement shall be determined annually; a property
  that becomes eligible for a year subsequent to the initial year in which
  such abatement is authorized by local law shall  receive  the  abatement
  for  such  subsequent year and for each year thereafter while it remains
  eligible and until the authorization for the abatement expires.  If  the
  enhanced  exemption granted pursuant to subdivision four of section four
  hundred twenty-five of this title is later discontinued or revoked,  the
  abatement   granted   pursuant   to   this  section  shall  likewise  be
  discontinued or revoked. If eligibility for the abatement or the  amount
  of  the  abatement  changes  after  the extension of taxes, the assessor
  shall notify the official responsible for the collection  or  refund  of
  taxes,  who shall calculate and impose or refund the difference in taxes
  accordingly.
    4. Computation  of  abatement  by  local  legislative  body.  (a)  The
  abatement  granted  pursuant to this section shall eliminate all or part
  of the tax that results from any increase in the general county tax rate
  applicable to the assessment roll finally completed in calendar year two
  thousand two as compared to the tax rate applicable  to  the  assessment
  roll  finally  completed in calendar year two thousand one. It shall not
  limit increases in tax that result from changes in  the  full  value  or
  taxable  value  of  property  or  from  subsequent tax rate increases or
  increases in taxes other than the general county tax.
    (b) The general county tax extended on an  eligible  parcel  shall  be
  abated by the abatement amount, which shall be calculated by multiplying
  the  taxable assessed valuation, after application of all exemptions for
  which such parcel is eligible for general county tax  purposes,  by  the
  abatement  tax  rate  determined  pursuant to this subdivision, provided
  that the abatement shall not exceed the  general  county  tax  otherwise
  chargeable to such eligible parcel.
    (c)  The local legislative body shall determine separate abatement tax
  rates for each class of property, each roll year and each portion of the
  county for which a general county tax rate is determined. The  abatement
  rate  shall  be  the base abatement tax rate calculated pursuant to this
  subdivision multiplied by the abatement ratio.
    (d) The abatement ratio shall be set forth in the local law, as it may
  be amended from time to time, which adopts the abatement  authorized  by
  this  section.  Such  ratio  shall  be  one-half  if  no  other ratio is
  specified in the local law. In no event shall  the  abatement  ratio  be
  greater than one.
    (e)  For  the general county tax levied on the assessment roll finally
  completed in calendar year two thousand two, the base abatement tax rate
  for a class shall  be  the  general  county  tax  rate  for  such  class

  applicable to such assessment roll, less the tax rate for such class for
  the roll finally completed in calendar year two thousand one.
    (f)  In  each  subsequent  year  the  base abatement tax rate shall be
  adjusted  to  account  for  changes  in  the  level  of  assessment   by
  multiplying the base abatement tax rate calculated pursuant to paragraph
  (e) of this subdivision by the ratio between the class equalization rate
  for  such class for the roll completed in calendar year two thousand two
  and the class equalization rate for such class for the  assessment  roll
  for such subsequent year.
    (g) If the equalized tax rate for a class in any year is less than the
  equalized  tax  rate for the roll finally completed in calendar year two
  thousand two but more than the rate for the roll completed  in  calendar
  year two thousand one, the base abatement tax rate shall be recalculated
  by dividing the difference between such equalized tax rates by the class
  equalization ratio for the roll year of the taxes to be abated.
    (h) If the equalized tax rate for a class and roll year after calendar
  year  two  thousand two is less than the equalized tax rate for the roll
  completed in calendar year two  thousand  one,  no  abatement  shall  be
  granted for property in such class for such roll year.
    (i)  For  purposes  of  this  section,  "class" shall have the meaning
  provided by section eighteen hundred two  of  this  chapter  and  "class
  equalization  rate"  shall  have  the meaning provided by section twelve
  hundred two of this chapter. The term "equalized tax  rate"  shall  mean
  the  general county tax rate for a class and roll year multiplied by the
  class equalization rate for such class and year.
    5. Cooperative apartment corporations, trailers and mobile homes.  The
  abatement  authorized  by  this  section  shall  apply  to taxes on real
  property owned by a cooperative corporation and to trailers  and  mobile
  homes  to  the  extent  such  taxes  are attributable to the property of
  eligible shareholders or owners and shall be credited against the  taxes
  or  rent otherwise payable by or chargeable to such eligible individuals
  in the same manner as is provided for the exemption granted  by  section
  four hundred twenty-five of this title.
    6.  Retroactive  implementation.  A local law adopted pursuant to this
  section may provide that benefits  shall  be  granted  retroactively  in
  respect  to  all  or  specified assessment rolls finally completed in or
  after the year two thousand two. Such local law  may  provide  that  the
  assessor  of  such  special  assessing  unit shall apply the retroactive
  abatement as a credit against current taxes for one or more years or may
  authorize the chief financial officer of the county to refund the excess
  taxes collected without interest in one  or  more  installments  over  a
  period of one or more years.