X-ray observations of pre-main sequence (pre-MS) stars of M-type probecoronal emission and offer a means to investigate magnetic activity at thestellar-substellar boundary. Recent observations of main sequence (MS) stars atthis boundary display a decrease in fractional X-ray luminosity($L_{X}$/$L_{bol}$) by almost two orders of magnitude for spectral types M7 andlater. We investigate magnetic activity and search for a decrease in X-rayemission in the pre-MS progenitors of these MS stars. We present XMM-NewtonX-ray observations and preliminary results for ~10 nearby (30-70 pc), very lowmass pre-MS stars in the relatively unexplored age range of 10-30 Myr. Wecompare the fractional X-ray luminosities of these 10-30 Myr old stars toyounger (1-3 Myr) pre-MS brown dwarfs and find no dependence on spectral typeor age suggesting that X-ray activity declines at an age later than ~30 Myr inthese very low-mass stars.
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