The project leader Edward Guo<ref>{{cite web|url=http://imslp.org/wiki/User:Feldmahler |title=User:Feldmahler - IMSLP/Petrucci Music Library: Free Public Domain Sheet Music |access-date=April 18, 2015 |url-status=dead |archive-url=https://web.archive.org/web/20150418150035/http://imslp.org/wiki/User%3AFeldmahler |archive-date=April 18, 2015 }}</ref>{{primary inline|date=August 2016}} claimed the changes were made because the level of funding was "not sustainable in the long run", but also noted:
: "<blockquote><poem>The income we receive from various sources have been enough to maintain the site so far, but I increasingly believe that this level of funding is not sustainable in the long run. We are not, like traditional music libraries, bound by the service of a conservatory, university or publisher, but rather can do things that traditional institutions are not willing to do, because we serve only musicians and music lovers. But everything is a tradeoff – we also do not have the funding infrastructure these traditional institutions have, and over the past few years I’ve frankly exhausted my imagination in searching for new realistic sources of funding for IMSLP.
: "And so I will announce here that a subscription system for IMSLP will be put in place. But this will not be a traditional subscription model – in particular, no file will be blocked from access by the public. Rather, a subscription will permit a member to download files without having to wait a certain number of seconds, eliminiate [''sic''] some of the advertising on the site, and a few other benefits. I see this as a way to both preserve IMSLP’sIMSLP's philosophy of open access and to secure IMSLP’s future."<ref>{{cite web |url=http://www.imslpforums.org/viewtopic.php?f=1&t=8187 |title=Upcoming changes |publisher=IMSLP Forums |access-date=2016-07-10 |archive-date=2016-06-13 |archive-url=https://web.archive.org/web/20160613134755/http://www.imslpforums.org/viewtopic.php?f=1&t=8187 |url-status=live }}</ref><ref name="Strad2016"/></poem></blockquote>
Guo attributed the change in funding to discussions with librarians at an [[International Association of Music Libraries, Archives and Documentation Centres|IAML]] conference in June 2015. Some contributors to the website expressed concerns that Guo had not properly attempted to raise donations, but without any prior warning, introduced the membership system to monetize their work.<ref>{{cite web |url=http://imslpforums.org/viewtopic.php?f=1&t=8187 |title=Upcoming changes |publisher=IMSLP Forums |access-date=2016-07-10 |archive-date=2016-06-13 |archive-url=https://web.archive.org/web/20160613134755/http://www.imslpforums.org/viewtopic.php?f=1&t=8187 |url-status=live }}</ref>
