To apply to become a U.S. citizen, you have to show that you have had good moral character for the last 5 years before applying. However, any period of time can be reviewed. Conduct prior to 5 years may be considered in certain situations. You also must show that you have good moral character for various immigration benefits, including cancellation of removal, citizenship, Violence Against Women Act (VAWA) benefits and others.

If you spent at least 180 days in jail during the last 5 years, you are not considered to have good moral character and must wait 5 years to apply for citizenship.

What is good moral character?

You do not have good moral character if, during the 5 years in question, you:

• Are drunk frequently,
• Have been convicted of 2 or more gambling offenses,
• Gave false information to get immigration benefits,
• Do not pay your taxes on time,
• Do not pay child support or alimony, 
• Were in prison for 180 days or more at any time,
• Break a law by having drugs (except 30g or less of marjiuana),
• Engage in prostitution,
• Smuggle a person to enter the US,
• Practice polygamy, or
• Engage in an extramarital affair.

You are permanently barred from establishing good moral character if you:

• Are convicted of murder,
• Are convicted of an aggravated felony on or after November 29, 1990, or 
• Are involved in persecution, genocide, torture, or severe violations of religious freedom.

The following can show that you have good moral character: 

• Education - school attendance records or transcripts,
• Work history,
• Volunteer or community service work,
• Military service and awards,
• Involvement in church or other religious organizations,
• Copies of any tax returns filed,
• Proof of property ownership,
• Proof you paid taxes on your income regardless if you are a lawful permanent resident or an illegal immigrant, and
• Statements by employers, teachers, and others.