I sell Medicare Supplements and Medicare Advantage Plans for people on Medicare. Also age 67 so work with it often. I agree the SSA (social security admiration) does a good job. All is not perfect and some things posted already are not as simple as has been stated. The FULL retirement age is not the same for everybody. No idea right off the highest age there is already out there in the law but it was moved from age 65 many years back. Also no longer is everybody auto enrolled in even Part A much less Part A and B. If you have elected to draw your SS or are already on Medicare due to a disability they will enroll you but if you are not drawing your SS they do not. The person must make the request to be enrolled.
If you are comfortable ono the internet it works well. You can also call their toil free number. IF YOU DO NOT enroll at age 65 you may have to meet with the local office. Not always necessary. but often is. If you do not enroll at age 65 in Medicare you MAY OR MAY NOT face a penalty. Many people are not aware of the rules here and it hurts them. IF YOU HAVE A LARGE GROUP COVERAGE, you will not face a penalty if you do not enroll in Part A or Part B until you loose the group coverage. Large group for this is I think 20 employees or larger. If you don't have large group you probably will have the penalty mentioned and it can be massive and never goes away. Same type thing happens with not enrolling in a qualified drug plan when on Medicare, no coverage but enroll later you have penalty for life. All those penalties are paid to the US government.
I strongly suggest if you are say age 63 you should be checking out your current coverage and verify if it will prevent a penalty to keep it or do you need to go on Medicare. Also realize you need to enroll in Part A and B about three months in advance of when you want it to begin. If you are enrolling in Part A and B when turning age 65 it happens normally smoothly and quickly. If you are say age 67 and are not enrolling it can take little longer and they will want proof of the coverage you have had since age 65 so they can see if you owe any penalty and if so what amount.
Medicare along with I will say Plan G Medicare Supplement to me is the best Medical Coverage I know of. No network, no referrals required by it, travels very well. Drug coverage is separate and there is no normal eye or vision care, but the medical coverage is great. The Medicare Advantage Plans can and many do include some of the additional coverage. Neither is perfect and each has it's advantage. I have been on each again as agent and like some things about each.
Word of advice to those who are near 65 and do not enroll in Medicare, be sure you keep records of the coverage you have and are able to prove if it meets Medicare basic standards to prevent the penalties. If it does you can enroll in Medicare any time of the year at any age with no penalty. Just allow at least three full months as they will want to verify your coverage during that time. If your coverage does not meet Medicare's basic coverage you can only enroll at a certain time and coverage is not effective for think 6 months and you have a penalty....none of that is good.
Also if you are under 65 and getting a Federal Tax Subsidy on your health insurance by Federal Law that subsidy ends the month your turn age 65 and you will owe all subsidy paid from the month you turn age 65 to this is caught. They have no way to pick this up at current time but it will be caught when your taxes are filled. If you are getting the Federal Subsidy you MUST by Federal Law file tax return.
One thing I run into semi often, if you have VA coverage for medicines, you should not have a penalty for NOT enrolling in a Drug Plan if you ever do. They consider the VA benefits to meet Medicare Basic standards for drug coverage. Know very little on Tricare but have been told over and over they should not enroll in any other insurance coverage. If you have VA only you should look into low cost options out there that "MAY" greatly benefit you.
It really is not complicated but there are some many things that can affect you and your options those can get confusing.