Hello, I am on H1B visa status since Oct 1, 2018. Prior to that, I was on F1 visa (since 2015). Will I meet the Substantial Presence test to file my taxes in 2020?

You will have met the five year test for the F-1 visa.  For the Substantial Presence Test 2020 requirements, add '1' to each year below.

"You will be considered a U.S. resident for tax purposes if you meet the substantial presence test for calendar year 2019. To meet this test, you must be physically present in the United States on at least:

   1. 31 days during 2019, and

   2. 183 days during the 3-year period that includes 2019, 2018, and 2017, counting:

• a. All the days you were present in 2019, and
• b. 1/3 of the days you were present in 2018, and
• c. 1/6 of the days you were present in 2017."

Review this IRS publication pages 4-6 for more information on the requirements of the Substantial Presence Test.