Agile is good where we have lots of changing requirements and for faster delivery but like in healthcare market most of the projects are deined on us REGULATION and policies which remain static and doesnt change like ICD10 requirements and always defined with delivery date
It is unlikely scope will get changed in ICD 10 or any intermediate delivery will help to determine pace of the projects

What in your opinion should we follow waterfall or Agile where scope is fixed and which is more efficient

Even for projects with static requirements, I think you still benefit by doing short, time-boxed iterations because the team creates the environment (requirements to production) for delivering much sooner. This shakes out the unknowns and problems in getting from end-to-end much sooner than waterfall. And you can measure the team's velocity in terms of user stories (or static requirements) that are completed each iteration, which gives more confidence in knowing where you are at any point in time. And, if the team is practicing test-driven development, your quality is higher and better known because it is visible in each demo or delivery.

Agile? hum. not necessarily.
But that depends on what you are defining as "Agile" The term has, of late, become mudied and misused.
Agile, as defined by Merriam-Webster is
1) marked by ready ability to move with quick easy grace <an agile dancer>
2) having a quick resourceful and adaptable character <an agile mind>

So an agileproject would be one that is defined by the ready ability to move with quick resourceful adaptable character. a "Static" requirement project would not need this.

HOWEVER. "Please raise your hands, those of you who's projects NEVER have change orders...What? NO one?" What a surprise!! So EVERY project needs to be flexible, able to change and adapt.

Every project has changes. I don't care if you are talking about a new website development program or a federally mandated project (Like the HIPAA 5010 project that I lead using 5 scrum teams) And oh by the way if I hadn't used Agile on the HIPAA 5010 project we would have failed. It totally saved the project. The story is too long to put down here. but i tell it often in my speaking gigs and classes.

If you are doing ICD-10 you are pretty familiar with HIPAA 5010 I bet. drop me a line and we can talk about how why agile worked for it.... oh yah and I am doing an "Experience Report" for the Community of Practice on this project and the experience. :-) So keep your eyes out for the experience report.