"He passed in 2014" means you can NOT CLAIM in 2015. If you have a dependent child you may be able to file as SURVIVING SPOUSE, but only if you have a child living with you.
Edited. 2/17/2016 4:05PM
You can still file Married Filing Jointly with your deceased spouse only in the year of 2014. You will still be using the normal form 1040. No special form is required. For the tax year of 2015, it depends on your marital status. You may file Single or Head of Household ( if you have a qualifying person), or file married if you remarried.
"He passed in 2014", so she can not file MFJ in 2015, at least not to the dead spouse.
Well, I will assume that if your spouse was alive in some part of 2015 it shouldn't be an issue. If you file electronically, Turbo tax gives you the option to be walked through your entire filing process. The system should let you know if your spouse still qualifies or not. Or, go to the IRS.gov website. I would definitely check to see what factors they use to determine spousal allowances. Hope this helps.
If he passed away in 2014, he couldn't be "alive in some part of 2015". The original poster asked if they could ALSO claim him in 2015, which assumes they already claimed MFJ in the year he passed (2014).