It really varies depending on where you live and what clinic you go to. If you are in North America there are free clinics, but they are often stricter than paid clinics (not that that is necessarily a bad thing) and can take longer to get accepted to. I would definitely consider detox or buprenorphine (Suboxone) before methadone, methadone should be an absolute last resort for when you have tried everything else and failed. It's very difficult to get off and the withdrawals are way worse and way longer-lasting than heroin. You don't have to be in withdrawal to take methadone, although some clinics may prefer it if you aren't noticeably high because they don't want you to overdose. You do have to be in withdrawal to go on Suboxone though. Suboxone you can get prescribed from a doctor (although not just any doctor, they have to be licensed to prescribe it) and you don't have to go to the clinic every day (or pharmacy every day in Canada) like with methadone.
There are a lot of threads on here about this topic already, please let me know if you need help finding any of them.
Actually it's only for the first 2 months. And after that (depending on your doctor and your situation of course) you can start getting longer and longer carries, whereas compared to methadone many doctors like to keep you on daily witnessed ingestion for years and will never end up giving you more than a few days at a time. For example, I've been on methadone for 10 years and had clean urine tests for the majority of that time, and I've finally gotten to only have to pick up my methadone once a week. So Suboxone still offers far more flexibility than methadone, even in Canada. But yes, I should have been more specific, I was assuming the OP was in the US (which they are), and meant that they wouldn't have to do daily pick-ups for very long with Suboxone compared to methadone or go to the methadone clinic in the US to pick it up.In Canada YOU do actually have to go to the pharmacy every day to dose Suboxone, at least for 3 months minimum before you can get any carries for Suboxone in Canada.