304 medical grade stainless is a true non magnetic stainless. Lower grades can be magnetic, and usually have a clear coat on top to inhibit rust.

My fridge is nothing fancy, Hisense from Lowe's, and it's magnetic.

Frigidaire is magnetic.

There is no such thing as Medical grade stainless. 304 is for general use in the austenitic (non magnetic) 300 series of stainless. Surgical stainless is usually 316 or 316L grade but there is no designated medical grade . 304 and 308Lis usually used in the food industry when food is in direct contact with the metal. All pot and pans are in the 300 family of stainless. (take a magnet when shopping for stainless cook wear to see if you're getting screwed.)

A refrigerator that is magnetic uses metal from the Ferritic 400 series of stainless and are usually 409 or 430 grade and cheaper. If you find a domestic retail refrigerator which isn't magnetic it's 300 series stainless, expensive and unnecessary.

I've used enough 300 series stainless to fabricate food processing equipment in the food industry and know a thing or two about the stuff.