The IRS has completed the distribution of $1,400 stimulus payments to nearly a million beneficiaries. However, some taxpayers may still wonder if they are eligible or if they can claim a missing payment.

Starting soon, those affected by the Windfall Elimination Provision and Government Pension Offset will see an increase in their monthly benefits.

Most will receive their one-time retroactive payment by the end of March, and new monthly payments will begin in April, the agency says.