How early can disk substructures, and hence signs of early planet formation, be found in young disks? The long-baseline observations of gaps in HL Tau’s disk has been a watershed event in empirically constraining planet formation in protostellar disks, strongly suggesting that planets are already forming by early Class II or late Class I phase. While disks around Class II objects have been studied systematically, their less evolved Class I counterparts, which are still embedded in dense envelopes, have only begun to be characterized. We have conducted ALMA continuum Band 6 long-baseline observations of the disk of Class I source IRS 63 to search for gaps in an even younger protostellar disk than HL Tau. IRS 63 is considered significantly less evolved than the famous HL Tau due to an obvious envelope detected at mm/submm wavelengths not found in HL Tau. The long-baseline observations allow for sub-arcsec resolution (<10 AU at the distance of IRS 63), key to studying any fine substructure that may be present in the disk due to early planet formation. The implications of the IRS 63 high-resolution observations for disk and planet formation are far-reaching because these data are the highest resolution available in a protostellar disk at such an early stage of evolution. We compare disk parameters—modeled in both the image and u,v-planes—to HL Tau and other disk observations.