Information from this MetroRiderLA post reformatted as a table. Also, the current SDM day pass fare ($1.50) was added.

current fareJuly 1, 2007 fareJuly 1, 2009 fareJuly 1, 2011 fare
Cash$1.25$1.25$1.50$1.80
Day Pass$3.00$5.00$6.00$7.25
Weekly Pass$14$17$20$24
Monthly Pass$52$62$75$90
EZ Monthly Pass$58$70$84$100
Senior/disabled/Medicare (SDM) cash fare$0.45$0.55$0.65$0.75
New SDM “off peak” fare (good 9 a.m. to 3 p.m., 7 p.m. to end of service day, and Saturday, Sunday, and all Federal holidays, which are not the same as Metro holidays, and good for only seniors 65+)--$0.25$0.30$0.35
SDM day pass$1.50$1.80$2.15$2.55
SDM monthly pass$12$14$17$21.00
SDM EZ Pass$29$35$42$50
K-12 monthly pass$20$24$29$35
College pass$30$36$43$52
No discounts provided for token customers or for owl service, or midday service on Lines 40 and 42. Semimonthly pass eliminated.
Zone charges per zone$0.50$0.60$0.70$0.85
SDM Zone fare$0.25$0.30$0.35$0.40
Zone stamps (per zone, same cost for EZ or Metro stamp)$15$18$22$26
SDM Zone Stamp$7.50$9.50$9.50$9.50
Interagency transfer$0.25$0.30$0.35$0.40
SDM interagency transfer$0.10$0.10$0.10$0.15
Estimated fare/boarding$0.60$0.71$0.80$0.87