Are you entitled to FREE NHS treatment on a work permit? (HSMP/Tier 1/Other)

Plus, I had an natioanl insurance number from when I worked here under Bunac in 99, but I didn't come back to live until 06.

I came back for holidays almost every year inbetween and had a NI #, but that doesn't mean I could use the NHS.

Exactly.  I have an NI number now, but I definitely shouldn't be using the NHS.

Agreed--an NI number by itself should not entitle you to NHS treatment.  That is true.  What I'm describing, however, is a real phenomenon of how policy is misconstrued in GP surgeries in NHS Lothian at the present time.  This is also true.

What readers should take into account in this thread, therefore, is the following:

1) NHS services are devolved; law or Department of Health policy may be UK wide, but expect regional differences in *procedure*, with the possibility of resultant error in relation to relevant legal mandate.  As the different experiences listed in this thread will attest to, you may be asked to provide different things in England vs. Scotland, in different trusts in England, different surgeries, etc.

2) With regards to what you're entitled to, don't expect to get accurate information from calling the trust.  At least in NHS Lothian, in my experience, most of the day-to-day employees you'll deal with will get it wrong--after all, most of my colleagues are Scottish and haven't given a second thought to UK visa issues.  Get your information from the Department of Health (posted by Webyj above), print it out, and take it with you to show the surgery/hospital.

3) The most expedient way to get the coverage you deserve is to bring as much evidence as you can--visa, contracts, NI number, Council tax bill, University acceptance letter, etc.--to the surgery to show proof that you live and work in the UK.  I'm not advocating that people should use an NI number to skirt the law.  What I'm saying is to expect to be asked for something that you shouldn't legally be required to show, then make a choice, a) show the document, or b) go through the time and effort of dealing with the relevant bureaucracy of your choice to fight the good fight.

Just to give you my anecdotal evidence dealing with the NHS as an ex-Pat. I came to the UK on Feb 16th, 2010. About 2-3 weeks after arrival having found a temporary flat (sublet) I found my local NHS GP accepting new patients (using NHS website) and went in to register. The person at the clinic said I should bring my passport and proof of address (i.e. a utility bill or a bank statement with my name and ADDRESS). She checked the bill to see the address but did not even look at my passport or Tier 1 visa.

As I was a student in the UK some years ago I saved my old NHS card with an NHS number (I never been to a doctor in the UK before). She took the number and said I will get a new card in the mail at some point. I then proceeded to book an appointment with the GP to get my prescription reissued. I did this about a week later and received a prescription.

The entire process was painless, the staff were courteous and while I did wait a little longer than in the US I was very happy with the service.

I finally have an NHS Number.
The only reason it took me some time, it was because I did not go register earlier, partly to avoid any issues/delays, and partly a pinch of laziness since it was not an immediate need.
We finally register at a local GP office, filled out an application, it asked about employment info and NIN number.  We did not have the NINs handy so we left them blank, said we could let them know later, but the lady said it was fine and not to worry about it.  A couple weeks later we got our NHS numbers by mail and we're all set up.   I think the app also asked how long have we been here and we said ~9months, which is less than 1yr but more than 6months, and I dont know ultimately what the criteria is; also we did/do have employment info, so I guess it would e different if being here for less than a year and no employment info.  Still all a bit confusing, but glad we're done with that and making progress...
thanks!