the YMCA may recognize it as a charitable contribution but they are not the IRS and don't write the tax code. if the monthly dues are under $250 the IRS does not require documentation to deduct it as a contribution since they are a 501(c)(3) org and each monthly contribution is regarded as a separate contribution. if more than $250 the IRS does require a written acknowledgment. The $250 rule applies to all charitable donations.
