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Meet ResidencyCAS, the New OB/GYN Residency Application System

As a recent residency graduate, I can attest to how stressful the application process can be. Luckily, a lot has changed for the better since I applied for OB/GYN residency in 2018 (which now seems like ancient history)!

You’ve probably heard by now that the specialty of OB/GYN will be changing the application process for the 2024/2025 application cycle. (If not, you’ve come to the right place!)

Previously, all specialties used the Electronic Residency Application Service (ERAS), but now OB/GYN will be using a platform called Residency Centralized Application Service, commonly referred to as ResidencyCAS.

Even though this is a big change to the application process, a ton of work has been done to make it a smooth, streamlined transition that’ll make your life easier instead of harder!

In this post, we’ll take a look at this new system, why it’s being adopted, and how it’ll make the residency application process easier.

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Changes to the OB/GYN Residency Application Process

Many of the changes made to the OB/GYN residency application process were brought about by the “Right Resident, Right Program, Ready Day One (RRR)” grant team.

So now, instead of spending a whole month waiting to get an email from a program, all interview invitations will be released on the same day, and residency programs have been strongly encouraged not to let the number of invitations exceed the number of interview spots.

The transition has also been improved by adding preference signaling (discussed in more detail below) and a transition to residency curriculum. All of these changes have been implemented to make the difficult transition to residency a bit easier, and improve the experience of residency applicants!

The next step in this improvement process will be the focus of this article: the new residency application system! OB/GYN applicants are pioneering the use of the new platform, and they’ll be the first to benefit from it.

Why Switch from ERAS to ResidencyCAS?

There were multiple reasons why the field of OB/GYN decided to move to the ResidencyCAS platform. Here are just a few:

1. View applications more holistically

The primary driver was the desire to allow for a more holistic review of applications.

Instead of solely relying on traditional academic metrics like test scores, the advanced data processing and customizability of the new system allows programs to focus on ALL aspects of the application, including research, community service and advocacy, leadership, and the path each applicant has taken to residency. 

This creates a more equitable application and review process, which is crucial to improving the entire transition from medical school to residency.

2. Cut down on costs

Another goal of the transition to the ResidencyCAS application system is reducing fees for applicants. The fee structure for ERAS vs ResidencyCAS is as follows:

ERAS: $99 for the first 10 applications, $19 for each application between 11-20, $23 for each application from 21-30, and $27 for each application over 30.

ResidencyCAS: $99 for the first 18 applications, $18 for each application between 19-30, and $23 for each application over 30.

On the surface, these may seem like random numbers, but they were deliberately chosen. As one of the specialties leading the implementation of preference signaling for residency applications, OB/GYN applicants have 18 signals to send to programs.

These 18 signals (three gold to indicate the highest interest and 15 silver to indicate very high interest) are the applicant’s way of letting a program know they are among the applicant’s top choices.

Analysis of preference signaling has shown that applicants have the highest chance of getting an interview at the programs they signal, and are much less likely to get interviews at programs they didn’t signal. You can still apply to as many programs as you’d like, just keep in mind that most applicants will only get interviews at programs they signal, so spending extra money on more applications isn’t necessarily in your best interests.

One of the purposes of signaling is to reduce the overall number of applications, which means that an applicant who only applies to the 18 programs they can signal would only have to spend $99 with ResidencyCAS, as opposed to the $251 it would cost with ERAS!

No matter how many applications are submitted, the applicant will spend less money than they would have in years prior. That can go directly into your coffee budget for intern year!

3. Improve user experience

Another benefit of the new application system is how user-friendly it is. ResidencyCAS makes it extremely easy to enter all the required information into the application. Plus, the platform is mobile-friendly, making it easy to fill out the application on the go during the busy fourth year of medical school!

All the data can be easily sorted by program directors, so the highlights of your application will be clearly visible at your top programs.

Take a look at ResidencyCAS in this video below!

Does This Affect the OB/GYN Match Process?

It’s important to remember that only the application platform is changing for OB/GYN, which means that the actual Match process doesn’t change.

At the end of interview season, you’ll make your rank list of programs that you interviewed at and submit it to the National Resident Matching Program (NRMP) and wait for that magical week in the middle of March!

The Supplemental Offer and Acceptance Program (SOAP) is a program that can be used by applicants who don’t Match, and the new application process won’t change this either.

Where Can I Find More Information?

There are a lot of resources that can be used for navigating the new application process in 2024. These include:

1. Advisors

The most important resource you have are the folks at your institution who work in an applicant advising or counseling role. That could be a program or clerkship director, an invested faculty member, or a medical school staff member, but if you have questions or concerns, this person will be your best resource.


If you don’t have access to a residency counselor of some sort, the APGO and ACOG websites are great sources of information about the entire residency application process.

APGO is offering a series of webinars to guide you step-by-step through the process. Here’s a general overview of the timeline (official dates will be available on the APGO website):

April: Informational session about best practices for applying to residency, covering topics from letters of recommendation to dual applications

May–June: The new residency platform opens officially, and a webinar on preparing your OB/GYN application will take place

July–August: Webinar covering where to apply and how to use preference signals

September: Applications due

3. Liaison

Additionally, the good folks at Liaison, the company responsible for ResidencyCAS, have a phenomenal support team that can help out with any technical issues you have with the application system. (Trust me on this one. I’ve met them, and they’re awesome!)

Further Reading

At the end of the day, I expect the new application platform to make applying to OB/GYN residency easier, cheaper, and more equitable.

Though there may be some anxiety about using a new product in its first year of implementation, the amount of work put into making this a seamless transition is staggering, so applicants need not worry. Rejoice in the fact that you’re entering a field that’s leading the way in improving the transition to residency!

Looking for more (free!) content to help you prep your residency application? Check out these other posts on the Med School blog: