The US budget surplus in Apr rose to the highest level since 2008 on record revenue as hiring improved during a month when Americans file tax returns.  Revenue exceeded spending by $157B, compared with a $107B surplus a year earlier, according to the Treasury Dept.  The estimate was for a $155B surplus.  Hiring bounced back in Apr as the jobless rate fell to 5.4%, the lowest since May 2008, from 5.5% month earlier.  That’s swelling Treasury coffers & improving the nation’s fiscal situation as spending gains 6.4% so far this year.  The Apr surplus was the 5th-highest on record for any month.  So far this fiscal year, which began Oct 1, the deficit declined to $283B compared with $306B in the same 7-month period a year earlier.  Revenue increased 13.9% in Apr to an all-time high of $472B, while outlays gained 2.5% to $315B.  The Congressional Budget Office, which estimated the Apr surplus at $155 billion, listed higher spending on Medicaid, Medicare & Social Security among the reasons for increase in outlays last month.