“I came to the U.S. almost 10 years ago. My green card will expire in March of 2013. I married an American citizen on January 1, 2010. I was told that I could apply for U.S. citizenship 90 days before January 1, 2013, after being married for three years."
 

“If this is true, how long will it take for my citizenship to be approved? And after that, how long before I am sworn in? I am worried about my green card expiring."
 

“Also, I have not worked in five years because of an illness. I am included on all of my husband’s tax returns. Do I have to show these tax returns to an immigration inspector, and if so, how many years do I have to provide?”

You will be eligible to apply for U.S. citizenship 90 days before the third anniversary of holding your green card – but not the third anniversary of your wedding date.

You say you were married on January 1, 2010, but you surely didn’t receive your permanent resident status on that date. If your green card is set to expire in March of 2013 then you must have received it in March of 2011.

Green cards issued through marriage to a U.S. citizen are conditional for two years. At that time – 90 days before the card’s expiration date, actually -- the married couple can jointly apply to have the condition removed and the card made permanent.  (The form for doing this is I-751; you can find it on the U.S. Citizenship and Immigration Service website at www.uscis.gov).

Once the condition removal is approved you will receive a new green card that will expire in 10 years, so there isn’t any need to worry about your green card lapsing while you apply for citizenship.

You will be able to file naturalization paperwork (N-400; also on the USCIS site) two years and nine months after the date you received your original green card.  Those married to U.S. citizens can apply for naturalization three years after green card issuance – the paperwork can be filed three months before that time.

You ask about citizenship swearing-in times, and they vary depending on where the application was filed. Some successful applicants can be sworn-in the day they pass their interviews; in other locations it might take longer.  At the swearing-in ceremony, the new citizen hands in the green card in favor of a naturalization certificate that can immediately be used to apply for a U.S. passport.

The processing time from paperwork submission to interview also varies. In the New York City office cases filed in October of 2011 are currently being finalized; upstate in Albany and Buffalo it only takes five months. These times can also be checked on the USCIS website.

It’s always a good idea to have tax returns ready to present in case the USCIS interviewer asks. As you are filing based on marriage you should have three years of returns.

The question of needing to show tax returns as part of the naturalization process is one that comes up fairly regularly. Some applicants have been asked to show the returns; others haven’t. It all depends on the interviewer.

But applicants are told by USCIS that they need to have the returns.  USCIS citizenship information form G-1151 clearly states, “Your tax returns are very important proof that you are eligible for naturalization. On the day of your interview, bring certified tax returns for the last five years (three years if you are married to a U.S. citizen). Certified tax transcripts may be ordered by using Internal Revenue Service (IRS) Form 4506-T available at www.irs.gov or calling 1-800-829-1040.”