Digital adherence technologies (DATs) are increasingly used for tuberculosis (TB) adherence support, but information about their costs remains limited. We used microcosting to estimate health system costs (in 2022 US dollars) of 99DOTS pill sleeves and video-observed treatment (VOT), implemented in demonstration projects during 2018-21. Local cost estimates for standard directly observed treatment (DOT) were also obtained. The estimated per-person costs of 99DOTS for drug-sensitive (DS-) TB were $98, $106, and $174 in Bangladesh (n=719), the Philippines (n=396), and Tanzania (n=976) respectively. The estimated per-person costs of VOT were $1 154, $304, $457, and $661 in Haiti (n=87 DS-TB), Moldova (n=173 DS-TB), Moldova (n=135 drug-resistant [DR]-TB) and the Philippines (n=110 DR-TB) respectively. Health system costs of 99DOTS may be similar to or cheaper than standard DOT. VOT is considerably more expensive; labor cost offsets and/or economies of scale may yield savings relative to standard DOT in some settings.