The Immigration Reform and Control Act of 1986 imposed civil and criminal fines for the unlawful hiring of aliens. A maximum penalty of six months imprisonment and a fine of $3,000 per worker may be imposed. For I-9 paperwork violations, fines range from $110 to $1,100 per employee involved. Employers are given a ten-day window to cure technical and procedural I-9 violations and a five-year statute of limitations period applies to substantive I-9 errors. Fines for knowingly hiring undocumented workers can be up to $11,000 for each worker. However, violations occurring on or after March 27, 2008, are subject to a maximum fine of $16,000.