The earnings limit for those like you who have not yet reached the full retirement age is $1,310 per month, or $20 more per month than in 2014. If you exceed this limit, you’ll lose $1 of benefits for each $2 of benefits over the limit.
Advance payment of current tax liability based either on wage withholdings or installment payments of your estimated tax liability. To avoid penalties, you generally must pay to the IRS either 90% of your final tax liability, or either 100% or 110% of the prior year’s tax liability, depending on your adjusted gross income.