Increases the volunteer firefighters' and ambulance workers' credit

Relates to increasing the volunteer firefighters' and ambulance workers' credit; increases the amount of the credit from $200 to $500 for single filers who have served for less than five years and from $200 to $1,000 for single filers who serve at least five years and from $400 to $1,000 for spouses filing jointly where one spouse has served less than five years and from $400 to $2,000 for spouses filing jointly who have each served at least five years.