Context :

Aims : Periodic variability in young stellar objects ( YSOs ) offers indirect evidence for an active dynamical mechanism .
Starspots , accretion , stellar companions , and disk veiling can contribute to the photometric variability of YSOs .

Methods : As part of an ongoing study of the \rho Oph star forming region , we report the discovery of 92.6 day periodic variations for the Class I YSO YLW 16A , observed over a period of three years .
A SED model was fit to available photometric data for the object .

Results : We propose a triple-system with an inner binary with a period of 93 days eclipsed by a warped circum-binary disk .
The nature of the secondary is unconstrained and could be stellar or sub-stellar .
We report the discovery of a tertiary companion at a projected separation of \sim 40 AU that could account for the circum-binary disk warp .
This light curve and model is similar to the model we proposed for WL 4 in previous work .
Understanding these systems may lead to insights about the nature of stellar evolution and planetary formation , and provide valuable benchmarks for future theoretical modeling and near- and mid-infrared synoptic surveys of YSOs .

Conclusions :