The poster is referring to a PGY 1-3 or PGY 1-4 program vs. a PGY 2-4 program. The following letter about ACGME EM residencies for DO's might be helpful:
"Should I complete the AOA internship?
There are currently five states that require the AOA internship in order to be licensed. These states are Florida, Michigan, Oklahoma, Pennsylvania, and West Virginia. The philosophy behind requiring the internship is that the AOA approved internship will give a broad primary care education during the PGY-1 year, leading to a well-rounded background before beginning a residency. However, the vast majority of allopathic EM programs (even 3 year programs) incorporate a well-rounded PGY-1 year. Many programs include general/trauma surgery, internal medicine, unit/critical care months, OB/GYN, etc. If one is pursuing a PGY 2-4 MD EM program, some residencies may accept your AOA internship as the PGY-1 year, others may not. We suggest contacting each program individually.
However, if you plan on applying to PGY 1-3 or PGY 1-4 programs, and intend on completing an AOA internship, be aware that funding may be an issue for your last year of residency. HCFA will pay for a three year or four year MD residency, but not if you complete the AOA internship and intend on completing a PGY 1-3 program. Your last year (PGY-3) will not be funded by HCFA.
Programs often view lack of funding with disdain. You may enroll in a PGY 1-3 EM residency in any of the five states without having to complete the internship, but may have licensing problems. However, you can have the PGY-1 year waived according to Resolution 42, titled Approval of ACGME training as an AOA-approved internship. Please refer to the AOA website for more details. If one is granted Resolution 42, the PGY-1 year will be accepted as the AOA internship, and you will be allowed to apply for a medical license in the five states mentioned above. We suggest you ask each program individually their views on the AOA internship.
Some programs may view the AOA internship as a benefit, others may perceive it as a negative due to funding. Most Program Directors and Residency Coordinators should be able to discuss their view of the AOA internship during the application/interview process. Current DOs in the program are also a good resource for questions regarding internship requirements. We suggest contacting the AOA for the most up-to-date information regarding internship approval requirements. There are many strong opinions about the validity of the Osteopathic Internship, one should seek the opinions of their colleagues for help with this complex decision."
http://www.emra.org/images/upload/DOsinEMResidencies.pdf