How Does One Sign Up For Medicare?

My dad turns 65 next week. How should he go about signing up for medicare? If he doesn’t get it done by his birthday, has he forefited coverage for any length of time?

Thanks!

Wow. Forty-five views and no one could help?

Assuming you are US-based, ever think of visiting this place?
[ul]
[li]https://www.medicare.gov[/li][/ul]

More specifically https://www.medicare.gov/sign-up-change-plans/get-parts-a-and-b/when-and-how-to-get-parts-a-and-b.html