I am US Citizen residing in India for the past 2 years. Do I need to fill both forms, namely 1040 and 2555?

.If your total worldwide income exceeds the filing requirement, you must file your U.S. tax return. On your return a U.S. citizen or resident must report your world wide income. If you paid taxes in the foreign country, you will claim credit for taxes paid in the foreign country by filing Form 1116 or can file form 2555 Foreign Earned Income Exclusion.

Another filing requirement is Form TD F 90-22.1. Your U.S. Tax Return: U.S. Citizen or Resident with Foreign Income (http://taxipay.blogspot.com/2008/03/us-citizen-or-resident-with-foreign.html)