This issue has variants.
The on-sale date is the publication date reported in U. S. Copyright Office filings.
Distributed to newstands in February 1963. This issue includes 10 pages of paid advertisements.
Distribution date from Joseph Marek's Marvel Comics Group history website.
Cover inks credit from Nick Caputo via the GCD Errors list, February 2009. Original indexer credited Dick Ayers.
Corner symbol of Ant-Man pencils and possible inks by Jack Kirby.
The Time Master never appears again, Ant-Man still operates in "Center City".
Text story with illustration.
This is a retelling of "The Rookie" from Marvel Tales (Marvel, 1949 series) #131 (February 1955). The idea of radiation granting super-powers to unborn children was a major part of early X-Men stories.