i will be 65 in 6 months,will social security automatically send me info to sign up for medicare part b ?

They will automatically send the information 3 to 4 months prior to your 65th birthday.

You are automatically signed up for Part B. If you don't want it you have to sign a form and send it back to them.

You have 3 month prior to 3 months after your birth month to get on a medical plan. There are Medicare Advantage plans (which is actually Part C) available, many for a $0 premium (average is around $35) and many include the Part D prescription drug coverage. You'll want to visit a local independent agent that deals in senior plans to find the best plan for your situation. Most of these plans pay your $131 Part B and $992 Part A deductible for you. They have small co-pays but they are usually less than the 20% that you pay on Part B.

There are also Medicare Supplement plans. The premium for these usually start out around $150 per month and don't include the Part D. If you get on a supplement you will need a stand alone Part D plan, which in my state runs $10 to $78 per month.