Algorithm & Rankings
How the Algorithm Works
How does the Match algorithm work?
The matching algorithm uses the applicant Rank Order Lists, the program Rank Order Lists, and the number of available positions at each program to find the best possible outcome for each participant.
The algorithm starts with an attempt to place an applicant into the program that is most preferred on the applicant's list. Each applicant's Rank Order List is traversed "downwards", from most preferred program to least preferred, until the first program is reached at which the applicant can be tentatively matched, or until the applicant's list of choices is exhausted. Each program accepts applicants "upwards" on its Rank Order List, continually removing less preferred matches in favor of more preferred applicants, until the program is matched to the most preferred applicants who wish to be matched to the program.Related Links:
Is there a video explaining the Match Process?
Yes, a video, examples and an interactive demonstration are available on the Matching Algorithm page.Related Links:
What is the best strategy for ranking?
In order to get your best possible result, you should rank your choices in order of your true preferences. Rank all programs to which you applied that would be acceptable. Do not rank any program that you would not want to be matched to under any circumstances.
The algorithm is specifically designed to give each participant their best result if they rank their choices in order of true preference. Using any other strategy may cause you to get a worse result for yourself. If you decide to order your preferences in another way (e.g., by how likely you think it will be to get into the program), you may not get the best possible result.Related Links:
How do I submit and certify my Rank Order List?
Applicants must submit and certify their Rank Order List online in the NMS Match System by the Rank Order List deadline. The Rankings User Guide includes information on how to:
- Add a program to your Rank Order List
- Delete a program from your Rank Order List
- Reorder a program on your Rank Order List
- Certify your Rank Order List
- Print your Rank Order List
What should I do if I do not want to submit a Rank Order List?
If you have accepted a position at a residency that is not participating in the Match, or if you decide not to submit a Rank Order List for either Phase of the Match for any other reason, you must withdraw from the Match.
If you plan to participate only in Phase II of the Match, you should not withdraw from Phase I of the Match. Your Participation Status in the NMS Match System should remain Active so you can participate in Phase II of the Match.
When you withdraw, you will be required to select a reason for the withdrawal. One of the options will enable you to indicate that you are withdrawing because you have no programs to rank (for example, because you received no interviews), but you are still interested in seeking a residency position in the Post-Match. If you select this option, you will be included in the list of unmatched applicants provided to programs with positions available after the Match. If you select any other reason for the withdrawal, you will be excluded from the list of unmatched applicants who may be seeking a position.Related Links:
Are the Program IDs in ADEA PASS different from a program's Match Code Number?
Yes. The 6-digit Match Code Number for a program is not the same as the program’s PASS ID. You can find the Match Code Number for each program participating in the Match on the List of Participating Programs.Related Links:
Can I rank a program where I didn't apply or receive an interview?
Yes, although it is highly unlikely that you will match to that program. Programs typically review applications, interview, and evaluate applicants to determine who they are willing to accept into the program. If you did not apply or interview with a program, it is unlikely the program is considering you for a position. If you are not ranked by a program, you cannot match to that program.
What should I do if the program I want to rank is withdrawn?
You should leave the withdrawn program ranked on your list. If you leave the program on your list and the program's participation status in the Match becomes Active before the Rank Order List deadline, that ranking will be used in the Match. If the program remains withdrawn, that ranking will not be used in the Match, and your list will be processed as if you had not ranked the withdrawn program.
I can't find the program I want to rank in the NMS Match System.
Only programs that are registered for the Match may be included on your Rank Order List. Consult the List of Participating Programs to ensure the program you want to rank is registered for the Match.
If the program is not included in the List of Participating Programs, contact the Program Director directly to clarify the program's participation status in the Match.
Within the NMS Match System, programs can be searched by Code Number, name of residency, location, program description, Program Director name, or program Code Number as they appear in the List of Participating Programs. ADEA PASS may have different names for programs than the NMS Match System, so be sure to search for programs using the information shown in the List of Participating Programs on this website.Related Links:
Can I change my rankings after certifying my list?
Yes. You can make changes to a Rank Order List that has been certified at any time prior to the Rank Order List deadline.
If you make changes to a list after it has been certified, you simply have to certify the list again before the deadline in order for it to be used in the Match.Related Links:
Can I view my Rank Order List after the deadline?
Yes. You will be able to view your Rank Order List for either Phase of the Match until 4 days after the release of the Match results for that Phase of the Match. However, you will not be able to change any information or certify a Rank Order List in the NMS Match System after the Rank Order List deadline.Related Links: