I have a question on whether I need to purchase turbo tax from Costco or can I I just file online since I have used Turbo Tax for the the past 4 or 5 years

[Critter-3]

It is your choice which program to use and where to buy it ... so make an informed choice.

[VolvoGirl]

How have you been filing?  Did you use the Online web version or the Desktop CD/Download program?  You can buy the Desktop program any where you want or directly from Turbo Tax.  Look for sales.  Costco does have a sale price right  now.  I just bought mine from Costco.  If you buy in the store  you get the CD but you can use the download method instead to install it.  If you buy from Costco online it is only for the Download install so you have to pick Windows or Mac.

Or you can start an Online web return here,

https://turbotax.intuit.com/personal-taxes/online/ 

[Opus 17]

In many ways, Turbotax Online is a completely different program than the desktop program you install on your own computer.  Some differences are

Desktop	Online
Your file is on your computer only.  You are responsible for backup and security.	Your file is in the cloud.  You can work on your tax return from any web-connected computer, and Turbotax handles backups and security.
You can prepare an unlimited number of returns from one installed program, and e-file the first 5.	Each tax return requires a separate online account with a different user name and password, and each online account will require a separate filing fee.
Deluxe, Premier and Home&Business version all contain the same forms.  More expensive versions contain extra help and support for complex situations.  You can prepare advanced returns with the cheaper Deluxe version if you don't need the extra support.	You must upgrade to the more expensive Premier or Self-Employed version if you have a tax situation that requires those features.
Can directly view and edit all forms and worksheets in Forms mode.  (Note that direct entry on forms may void the accuracy guarantee and/or block e-filing.)	Can't view any forms until after paying the fee, can't directly edit forms, must use interview mode.
Requires a relatively up to date operating system.	Works with almost any browser, even on older Macs and PCs.
Free telephone support includes help using the program as well as some basic tax advice.	Free telephone support only includes help using the program.  For tax advice, online users must upgrade to the Turbotax Live version.
Live expert assistance not available	Expert assistance (Live Assistance or Live Full Service) is available at an extra cost
No free version (you must pay for the software up front)	Simple returns may be free to file.
Discounts may be available from reliable third party sellers (Amazon, Costco, others)	Must purchase directly from Turbotax, prices subject to change at any time.
Must purchase the software up front but there is a 60 day money back guarantee if you are not satisfied	Only pay when you are satisfied with your return and ready to file, no refunds after that.