Do I need a plumbing permit in Baltimore County? Yes for all of it: who can pull one, and 22,473 permits

The county's rule

Baltimore County Permits, Approvals and Inspections (PAI) permits every address in the county, because the county has no incorporated towns: Towson, Catonsville, Dundalk, Essex, Pikesville and the rest all go through PAI. Baltimore City is separate. Two lines on the county's pages settle the question (read 24 October 2026):

There is no published exempt list and no homeowner exception on those pages, so a water heater, a new bathroom, a sewer line or a gas line for a range or dryer all start with a licensed contractor. The county runs its own plumbing and gasfitting licensing, with its own Plumbing and Gasfitting Board, so ask your contractor for the Baltimore County license number, not only a state one.

Who does what

How to apply and get it inspected

1. Your licensed plumber or gasfitter applies to PAI; the county's pages link "Plumbing and Gasfitting Permits" and "Plumbing and Gasfitting Fees" from the Plumbing Inspections page. The fee amounts were not readable on the pages we checked, so ask the contractor for the permit fee line on the quote.
2. Inspections are scheduled with the Bureau of Plumbing Inspections, 111 West Chesapeake Avenue, Room G24, Towson, 410-887-3620, paiplumbinginspections@baltimorecountymd.gov, Monday to Friday 7:30 a.m. to 3:30 p.m.
3. When the work passes, the county marks the permit COMPLETE, which you can see on its Permit Search map.

What 22,473 Baltimore County plumbing permits show

Plumbing permits peak in March, not summer, and residential gas permits slightly outnumber residential plumbing ones. Unlike the county's building permits, which rarely get closed in its system, trade permits do get marked complete, so a plumbing permit that still shows open a year on is worth a call to 410-887-3620. Monthly counts are on Baltimore County plumbing permits, every kind of work on Baltimore County permit statistics, and the rows on browse Baltimore County permits.

Before the plumber starts

Look up existing permits on your address with the county's Permit Search map, as the Baltimore County building permit search guide explains (add the Plumbing and Gas layers, not just Permits). Rules elsewhere: do I need a permit for plumbing repairs, a water heater and a gas line; labor costs in plumbing labor cost.

What this does not tell you

The county's permit files name no contractor and carry no job value on trade permits, so we cannot rank plumbers or show costs, and they have no final inspection date, so we show no time to final. Baltimore City permits are not included.