My Massachusetts T pass (commuter expense) was taken out of my paycheck pre-tax but was not reimbursed. Does this qualify for a commuter deduction?

You already got a tax benefit by having your employer pay for your MBTA pass with pretax money. You can't take another tax benefit on that money by filing for the Mass Commuter Deduction.

http://www.mass.gov/dor/individuals/filing-and-payment-information/guide-to-personal-income-tax/dedu...

Hi, I also got an MBTA monthly pass (perq) with pre-tax dollars, but my employer did not pay for the pass. Can I still claim the commuter deduction on my taxes? I haven't been able to find a clear answer. Thanks!

No.

If you paid for the pass with pre-tax dollars, you also cannot deduct the commuter deduction as your income was never taxed.  Therefore, you would be getting double tax benefits if you were to take the deduction.  This is not allowed.