  We present strategies to search for heavy neutral Higgs bosons decaying to
top quark pairs, as often occurs at low $\tan \beta$ in type II two Higgs
doublet models such as the Higgs sector of the MSSM. The resonant production
channel is unsatisfactory due to interference with the SM background. We
instead propose to utilize same-sign dilepton signatures arising from the
production of heavy Higgs bosons in association with one or two top quarks and
subsequent decay to a top pair. We find that for heavier neutral Higgs bosons
the production in association with one top quark provides greater sensitivity
than production in association with two top quarks. We obtain current limits at
the LHC using Run I data at 8 TeV and forecast the sensitivity of a dedicated
analysis during Run II at 14 TeV. Then we perform a detailed BDT study for the
14 TeV LHC and a future 100 TeV collider.
