The officer's rank relative to others in the cadre. Name and Category: General, SC, ST, OBC, or PwBD.

Crucial for calculating "Level" progression. Railway Zone: The current posting (e.g., NR, ECR, SWR). How Seniority is Determined

Seniority is often tied to the date an officer is regularized in their grade.

The principles for determining seniority are governed by the Indian Railway Establishment Manual (IREM) .

When specialists (Directly Recruited DMOs or Sr. DMOs) join the service, they are "interpolated" or merged into the existing seniority list of ADMOs based on complex weightage formulas.

For direct recruits joining as Assistant Divisional Medical Officers (ADMO) through the Combined Medical Services Examination (CMSE), their initial seniority is based on their UPSC rank.