A security deposit is money you hand your landlord before you move in. They hold it in case you leave damage behind or owe rent. Leave the place in good shape and paid up, and the money comes back to you — the law says so, with deadlines.
The deposit is not rent, and it is not a fee. It is more like a promise held in cash: “if I break something or skip out owing money, it comes out of this.” If neither happens, it is still your money and it comes back.
How much is normal
One month's rent is the classic amount. Some states cap it by law — one or one-and-a-half months is common — and some landlords charge less for strong applications. Whatever the amount, it should be spelled out in your lease, along with where the money is held.
Rent is $1,200 a month and the deposit is $1,200. You move out leaving the place clean but with a $150 professional cleaning charge the lease allows and $0 rent owed. You should get $1,050 back — with a written list showing exactly what the $150 was for.
Damage versus normal wear
This is where most fights live. Damage is on you: broken blinds, a hole in the wall, pet stains in the carpet. Normal wear and tear is on the landlord: paint that faded over two years, carpet worn down in the walkway, a few small nail holes. Living in a place leaves gentle marks. That is expected, and your deposit is not supposed to pay for it.
Getting it back
Most states give the landlord a set window after you move out — often 14 to 30 days — to return the deposit or send an itemized list of what they kept and why. Two moves protect you: take dated photos the day you move in and the day you move out, and give the landlord your new address in writing so there is somewhere to send the check.