Each year the IRS adjusts certain tax numbers for inflation and tax law changes. Here are some of the adjusted numbers you’ll need for your 2012 tax planning.

• Standard mileage rate for business driving remains at 55.5¢ a mile. Rate for medical and moving mileage decreases to 23¢ a mile. Rate for charitable driving remains at 14¢ a mile.
• Section 179 maximum first-year expensing deduction decreases to $139,000, with a phase-out threshold of $560,000.
• Transportation fringe benefit limit decreases to $125 for vehicle/transit passes and increases to $240 for qualified parking.
• Social security taxable wage limit increases to $110,100. Retirees under full retirement age can earn up to $14,640 without losing benefits.
• Kiddie tax threshold remains at $1,900 and applies up to age 19 (up to age 24 for full-time students).
• Nanny tax threshold increases to $1,800.
• Health savings account (HSA) contribution limit increases to $3,100 for individuals and to $6,250 for families. An additional $1,000 may be contributed by those 55 or older.
• 401(k) maximum salary deferral increases to $17,000 ($22,500 for 50 and older).
• SIMPLE maximum salary deferral remains at $11,500 ($14,000 for 50 and older).
• IRA contribution limit remains at $5,000 ($6,000 for 50 and older).
• Estate tax top rate remains at 35%, and the exemption amount increases to $5,120,000.
• The annual gift tax exclusion remains at $13,000.
• Adoption tax credit decreases to $12,650 for adoption of an eligible child.