ERAS and NRMP are two different systems. Here is what each one actually does.

Dear Applicant,

Almost every panicked September question comes from the same root confusion: people treat the residency application as one machine. It is two. They are run by two different organizations, they have two different calendars, and doing everything right in one of them does not enter you into the other.

Here is each one, in plain terms, with its real dates.

ERAS is run by the AAMC. It is the thing you build, the thing your letters land in, and the thing that gets delivered to program directors.

The AAMC's own 2027 timeline gives it two dates that decide your September:

Notice the gap between 1 and 2. You can submit on September 2, and nobody reads anything for three weeks. That gap is the single most misunderstood thing about the fall, and it is why a rushed submission buys you nothing: the September 2 trap.

September 23 is also the morning your MSPE becomes visible to programs, in the same sentence of the same AAMC timeline. If you have never seen what is in that document, read this before the 23rd: the MSPE explained.

NRMP is a different organization running a different system, called R3. ERAS delivers your application. NRMP runs the algorithm that turns interviews into a result.

Its three registration dates, verbatim from NRMP:

Ranking, Match Week and Match Day have their own dates, and they are all on our calendar page: Match 2027, every date that matters. This page is about the three above, because those are the ones you can miss.

This is the part worth reading twice.

Nothing on the ERAS timeline registers you with NRMP. NRMP registration is its own act, in its own system, on its own date, and NRMP lists it as its own line item: registration opens September 15. Your ERAS application can be submitted, delivered, reviewed, and interviewed on, and you can still not be in the Match.

It takes about ten minutes. It opens the same week most people are still refreshing their application status.

The one piece of real news in the calendar is that January 29 is described as the standard registration deadline, with, in NRMP's words, a "$50 additional fee for registration after January 29."

The actual last door is later, and it is easy to miss because it is buried in a line about something else. On March 3, 2027 at 9 p.m. ET, the same moment as the Rank Order List Certification Deadline, NRMP lists the "Applicant late registration deadline for the Match and SOAP."

So: register by January 29 and pay nothing extra. Register between January 30 and March 3 and pay $50. Miss March 3 and you are not in the 2027 Match at all. Do not build a plan around the second option. Interview season is a bad time to be handling paperwork you could have finished in September.

Not matching is not the worst case. Not matching and not being eligible for SOAP is.

SOAP is the process that places unmatched applicants into unfilled positions during Match Week. NRMP's most recently published applicant SOAP guide, written for the 2026 Match, opens its eligibility list this way:

Registration is criterion one. The 2027 guide is not published yet, and we will link it here when it is, but the structure has been stable for years and the 2027 calendar already ties late registration to "the Match and SOAP" in a single line.

If you want to know how SOAP works before you are in a position to need it, that is the cheapest hour you will spend this fall: SOAP explained, before you need it.

Two calendar entries, right now, in your phone:

That is the whole job for September. The rest of the fall is interviews.

Alex