K-1 fiancé visas are processed at US Embassies abroad, meaning the medical is the DS-2054 with a Panel Physician — not the I-693. Each embassy maintains its own list of approved physicians.
How to find your embassy’s panel physicians
Search travel.state.gov for your interview embassy and look for the “Medical Examination Information for Immigrant Visa Applicants” page. It lists the local panel physicians and their fees.
What’s tested
Same screening as the I-693, but the form is the DS-2054 and the chest X-ray is required for everyone 15 and older (not just IGRA-positives like the I-693).
After arrival in the US
K-1 holders who adjust status to a green card within the 90-day marriage window typically do NOT need a new I-693, provided the original DS-2054 was within the validity window and the case has no new admissibility issues.