Eliminating photolithography from solar cell processing is a significant opportunity for cost reduction for III-V solar cells. In this work, we test femtosecond IR laser ablation and scribing as an alternative to contact photolithography and wet chemical etching for mesa isolation, when processing multijunction cells. Laser ablation would lower production costs by increasing throughput as well as removing expensive chemicals such as photoresist.  We demonstrate that upright multijunction solar cells isolated by using the laser as a scribe to cleave through the substrate of the cell had virtually no performance loss when compared to a baseline cell processed with photolithography. By contrast, cells isolated by laser ablating through the active layers have performance losses that cannot be fully eliminated with post-processing etches, though there is current work to optimize the laser system to reduce damage. Additionally inverted solar cells structures are being investigated currently to develop a method of laser mesa isolation. So far no laser mesa isolation methods have been viable for producing inverted solar cells with good performance characteristics, though current exploration into this subject is being made. This demonstration of photolithography-free mesa isolation of upright solar cells with no performance losses is promising for less expensive III-V manufacturing.