[medical plans premiums paid for at work but not on T4 can they still be claimed

[overtaxed58]

You can only claim the portion that you paid. The part that your employer paid is not deductible.

[sfaysal]

You can deduct the premiums you pay for health insurance coverage, unless your employer pays for your coverage through a payroll deduction using pre-tax dollars. If so, you've already received a tax benefit for your premium payments, so don't deduct those premiums on your tax return. If you're not sure, consult your employer's benefits department.