This is pretty common in the insurance industry. As far as being a scam, I doubt it. It's either an agency, call center, or "lead house" trying to get you to send in the request to get "free information about Medicare."
If it's an agency/agent sending it, you would likely get a call one agent/broker.
If it's a lead house, it could be sold to several agents (3-10), so expect your phone to start ringing and possible someone showing up at your front door.
If it's a call center, expect your phone to explode with phone calls for various numbers.
At worst, it could be a scam, but I seriously doubt it.
Although I don't do this type of marketing, there are plenty who do. They are trying to get you to return the card so they can contact you about either medicare supplement plans or medicare advantage plans.
If you want to see what these mailers look like, just google "direct mail medicare supplement lead example" or "direct mail final expense examples." Most mail houses who send these out have examples on their websites.
Here is my advice if you care to read a bit more:
Don't fill anything out that looks generic. Anything for Social Security will have their logo on it. Anything from Medicare will have the CMS (Center for Medicare and Medicaid Services) on it. THe mail piece can be vague, but it CAN NOT impersonate a Federal agency. If you are not sure, call Social Security at 800-772-1213 or Medicare at 800-633-4227. If it looks generic, I would likely toss it.
If you want to learn what you need to know about Medicare, read these pdf's from the government.
https://www.medicare.gov/Pubs/pdf/02110-Medicare-Medigap.guide.pdf - or just Google "Choosing a Medigap Policy {insert year}".
https://www.medicare.gov/pubs/pdf/10050-Medicare-and-You.pdf - or google "Medicare and You {year}"
When it comes to picking a plan, talk to a broker who represents many companies. There is no cost to work with them. The amount the company pays the broker is included in your premium, either the company pays the broker or the company keeps it themselves. You don't get a discount by going with the company direct. You actually lose out, because I can guarantee the company rep you go direct with will never call you back and let you know their competitor has a better deal. If your broker is worth anything, he/she will.
For the most part, brokers (like any profession, there are bad one out there too) are good people who want to help you get the best deal at the best rate. They save you tons of time and money. Who want to spend hours shopping rates, comparing coverage, calling companies for info? They help with your Part D reviews. When the rate of the company gets too high, a simple call to your broker can quickly review all the options and help you find a lower rate if possible.
I get referrals all the time from people who did it on their own when they first started Medicare. A lady in TN signed up direct with a big carrier 4 years ago. My client referred her and we reviewed her coverage. We moved her to another A rated company, and she saved $1,013 a year...with the exact same coverage. I don't say this to brag, but just to let you know that brokers can really help you in a time where controlling expenses is important.
Although I am not on here often, I am happy to answer any questions. I hope this was helpful.
Rusty