This article comes straight from the Pilates Method Alliance website but it says it all, not just from a US perspective but a global one.

“First generation Pilates teachers, who knew Joe, maintain that he and Clara would be very happy and proud of the popularity and growth of Pilates. However, it is less clear how he might feel about the influx of "quickie trainings" available for would-be instructors wanting to be trained in a weekend or two. Joe worked at length with his own teachers, allowing them to assist and then finally teach after sometimes as long as 2 or 3 years of training and apprenticeship.

He was quoted as saying, "Remember Rome was not built in a day", and "Patience and persistence are vital qualities in the ultimate successful accomplishment of any worthwhile endeavor."
While Joe was the outspoken force behind his method, his wife Clara quietly incorporated his concepts and exercises in ways that benefited more seriously ill or injured clients. Her approachable style and special techniques spawned a dedicated lineage of teachers whose work flows through and uniquely colors the landscape of the Pilates method today. It is perhaps because of Clara that Pilates is clearly recognized as a positive form of movement-based exercise that truly can be tailored to any level of not just fitness, but also of health.

While excellent training programs exist in the marketplace today, some are clearly condensed and homogenized, producing less-than-adequately qualified teachers. Prices for classes range from $10-$20 for group mat sessions, to upwards of $50-$100 for one hour of one-on-one instruction utilizing the full repertoire of Pilates equipment.

Comprehensively, competently trained and knowledgeable teachers are the essential element in realizing one's potential as a client, and enjoying the process of learning Pilates.

To define, maintain, and support the commitment to training and education of Pilates teachers, the Pilates Method Alliance was formed in 2001 as the international professional association for Pilates teachers. In 2005 the PMA launched the PMA® Pilates Certification Exam. This 3rd party, psycho-metrically validated competency exam was designed to ensure that Pilates teachers are competent and safe to teach Pilates to the public. It is the only independent measure of Pilates teaching competency available today, and has no commercial relationship to any teacher training program.

Today, the number of PMA Certified Pilates Teachers is growing quickly, with Pilates teachers around the world embracing this common standard of competency and safety as a mark of professionalism.

With the development of the PMA globally - there are now many PMA Chapters around the world, the growth of iCREP and the continuing development in all internationally recognised training organisations, everyone has access to the pioneering work of both Joe and Clara Pilates and that has to be a good thing.”

Pilates Method Alliance
From the chair of the PMA UK Chapter, Alan Herdman May 2015

“The mission of the PMA Chapter and what I have personally hoped for, for a number of years, is the creation of a harmonious community of UK based pilates teachers of all trainings, levels and lineages to encourage sharing, networking and friendly interaction.

We need to move away from the "what I do is the correct way and your's is not culture" instead we must accept there are different ways of doing the same thing, different styles that are all acceptable if they are for the well being of the client or student. All important distinction REPS recognises mat teachers through completing an approved course. Many of these approved training courses are very short.
PMA certifies comprehensive teachers through sitting for an accredited exam. Eligibility to do the exam is based on completing a minimum 450 hour training programme covering mat and all apparatus at all levels.

The International Confederation of Registers of Exercise Professionals has eight members, Australia, Canada, Ireland, New Zealand, South Africa, United Kingdom, USA and United Arab Emirates. (10 now, also includes Belgium and Poland)

US REPS is the newest and largest - 160,000 members - and the only way to be identified as a pilates teacher is through PMA certification. This is because PMA is the only certifying agency offering an NCCA (National Commission for Certifying Agencies) there are seven certifying agencies involved in US REPS and the PMA is the only one with a pilates certification.

A mapping process is beginning between the eight different registries to see what is equivalent to what in each registry. There is no equivalent to the PMA's Level 4 comprehensive certification in any other registry.

The opportunity now exists for other registries to create a comprehensive standard (or adopt the PMA's standards of skills, knowledge and abilities) and create coursework that will map to that standard. Time will tell if the other registries feel it will be on their agenda or not. In the meantime, PMA certification is the only nationally accredited comprehensive certification for pilates in the world.

The PMA absolutely does encourage mat only teachers to join the organisation, We encourage unity, sharing networking and friendship between all pilates teachers regardless of their lineage, training level or school. We are all in this together and we can nurture each other and our profession by being friendly and supportive of each other. There is a UK Chapter of the PMA which extends the invitation to all Pilates Teachers. 

ALL ARE WELCOME”

Alan Herdman 2015