Do I need transit visa for South Korea?

According to Korea Immigration Service's website, as long as you hold valid visa for the United States, you do not need visa to enter Korea during your transit.

Because the journey starts from the U.S., and you're indian and working in the U.S. so you must have an U.S. visa, this applies...

Tourists in transit to Third Countries

1. Eligible Applicants

Citizens of all countries except Syria, Sudan, Iran, Macedonia, Cuba, Republic of Kosovo, Palestine, Afghanistan, Iraq, Nigeria, Ghana, Yemen, Gambia, Senegal, Bangladesh, Kyrgyz, Pakistan, Somalia, Uzbekistan, Nepal, Cameroon, Sri lanca, Myanmar (Burma), Egypt

2. Requirements

Persons who hold a visa (re-entry permit, permanent residency, etc.) to enter the United States, Canada, Australia, or New Zealand (hereinafter referred to as “the four advanced countries”) and

1) who go to one of the four advanced countries in transit through Korea; or

2) who stay in one of the four advanced countries and take a direct flight from the country to Korea to go to a country of nationality or a third country.

Please be noted that:

• If you are a U.S. visa holder who transit through Korea and Saipan to reach the U.S. as the final destination, you are permitted to enter Korea without a visa. (However, if you depart from the U.S. and enter Korea via Saipan, you are not granted no-visa entry to Korea.)

• If you are a Chinese group tourist holding a group-tourist visa to Japan and meet certain requirements (e.g. using a travel agency that only attracts Chinese group tourists), you are permitted to enter Korea without a visa.

• If you hold an e-visa to Australia and a visa label is attached to your passport, you are permitted to enter Korea without a visa. However, if the label is not on your passport, you are granted no-visa entry only when you depart from Australia and transit through Korea.

3. Condition of Permission

You have a flight ticket that is scheduled to depart from Korea within 30 days, and have never violated laws (e.g. overstay, etc.) after entering the United States, Canada, Australia, or New Zealand.