I am retired and get my medical insurance through my old company. Are those premiums deductible?

Yes you can deduct health insurance payments you made if you itemize and are able to claim medical expenses.

Possible Itemized Deductions are:

• Medical and dental costs above and beyond 7.5% of your AGI 
• State, local, real estate, and personal property taxes ($10,000 limit)
• Home mortgage interest
• Charitable donations and gifts

The Itemized Deduction will only be beneficial if you are over the Standard Deduction amount.

Standard deductions for 2020 

• Single - $12,400 add $1,650 if age 65 or older
• Married Filing Separately - $12,400 add $1,300 if age 65 or older
• Married Filing Jointly - $24,800 add $1,300 for each spouse age 65 or older
• Head of Household - $18,650 add $1,650 if age 65 or older