Coach Medellin is beginning his 30th year as a coach at Esperanza High School. Under his skillful coaching the Lady Aztecs have won 11 League Championships. They have won four Orange County Championship titles ('98, '01, '02, and '03). In CIF Southern Section, the Lady Aztecs have had six CIF SS Runner-ups ('92, '94, '97, '98, '99, '07), and one 3rd place finish in 2006. They have three times been California State Runner-ups ('97, '98, 07) and have won one CIF SS Championship in 1996. Coach Medellin has been named Orange County Register's Cross Country Coach of the Year three times. He has coached over twelve Track & Field CIF SS champions and three Track & Field News All-Americans, and was named 2010 Orange County Register's Men's Track Coach of the Year. The Lady Aztecs have won 178 dual meets out of 212 meets for an 84% winning percentage under Coach Medellin. The Lady Aztecs have had 11 undefeated seasons in Cross Country.

Coach Medellin has served on the CIF Coaches Advisory Board and has represented the California Coaches Alliance at the CIF board meetings. He has authored several rule changes over the last 30 years, most recently allowing teams to have more than nine runners eligible to run in the CIF prelims and finals. Coach Medellin has also written several articles for www.coacheseducation.com and Track & Field News on the steeplechase and coaching high school athletes.