It looks like they've been phasing it in. This is from March last year: https://techcrunch.com/2017/03/22/medium-debuts-its-paid-membership-subscription-program

It looks like they've been phasing it in. This is from March last year: https://techcrunch.com/2017/03/22/medium-debuts-its-paid-membership-subscription-program/ https://techcrunch.com/2017/03/22/medium-debuts-its-paid-mem...