Why did my Long Island property tax bill go up?

Diagnostic checklist (work in order)

• Step 1: Compare assessed values — If your Total Assessed Value or Taxable Assessed Value changed, the assessor reassessed you. Common in Nassau (every year). If significant, file a grievance.
• Step 2: Compare exemption section line-by-line — Most common cause of unexpected increase. Lost STAR (didn't renew, income too high, ownership changed), lost Senior (didn't return IVP letter), or lost Veterans (filing lapsed).
• Step 3: Check school district rate — Schools account for 60-75% of bill. A 5% school district rate increase translates to ~3-4% total bill increase. Compare current year rate to prior year on the bill.
• Step 4: Check county and town rates — County: ~$3-4/$1k. Town: $2-5/$1k. Both can change annually. Generally smaller impact than school rate changes.
• Step 5: Check village rate (if you're in one) — About 60 LI villages. Village rate can vary 5-15% year over year, especially after a budget vote.
• Step 6: Check special districts — Fire district, library district, ambulance, sewer, water — each can change independently. A new bond issue at the fire district level can add $50-$200/yr.
• Step 7: Check for new home improvements — If you renovated/built last year, the assessor may have added the improvement to your bill this year.

What to do once you find the cause