Hi, I need to file US tax returns for year 2015. I was on F1 since 2011 August.

For year 2015 I was on:
F1 (OPT) - Jan 1 to Sep 30
H1B - Oct 1 to Dec 31

As of Dec 31 I was single, nobody can claim me as dependent.

Here are the questions I have:
1. What forms should I be filling.
2. Which deduction should I use? (Standard 6300 or itemized?)
3. How much should the deduction be?

One person tells me that since I was on F1 only from Jan to Sep my deduction should be 6300 x (9/12) = 4725

4. I have tried using two software (1 - University provided, 2 - Glacier tax) and both provide same values: if I include H1B dates in the Visa history for 2015, it says I owe the IRS $800 bucks. If I don't include H1B (i.e. put only F1 from Jan to Sep 205) it says IRS owes me. This is really confusing. I usually get refund (even during CPT/OPT days since 2013) from IRS.

5. I can forego putting H1B dates in 2015 in these software but in the generated 1040NREZ form there is a field in Schedule OI - E and F. They are
E: If you had a visa on the last day of the tax year, enter your visa type. If you did not have a visa, enter your U.S. immigration
status on the last day of the tax year.
F: Have you ever changed your visa type (nonimmigrant status) or U.S. immigration status?

Please help. I know this is asked at many places but I am not getting a conclusive answer.

You will file Forms 1040NR or 1040NR-EZ and Form 8843 ONE LAST TIME, plus the state tax return.

I need to know your home country to tell you about the standard deduction. I SUSPECT you are Indian, but I cannot be sure.

If you ARE Indian, you claim the $6,300 standard deduction for the entire year under Article 21(2) of the U.S.-India Tax Treaty.

Item E: H-1B

Item F: Yes. Date of Change: 10/01/2015, F-1 to H-1B

@AtlantaTaxExpert, thank you very much.

One more question.

In form 1040 NR - EZ, there is item G on page 2 that asks for all dates I entered and exited the United States. When I was filing for 2014 and earlier (being on F1 for the whole year each time) I remember leaving this table empty. What should I do for this year? Should I enter Jan 18 (I was NOT in US from Jan 1 to Jan 18 since I was on a vacation to India) and put exit date as 31st Dec OR should I put Jan 18 and Sep 30 (F1's ending year) or Oct 1 and Dec 31 (H1B period)? Or should I leave it empty since I am filling 8843 as well anyway?

Please help.

Put the dates you actually left and re-entered the U.S. for whatever reason.

If you never left the U.S. in 2015, leave it blank!