There are many different laser wavelengths utilized for many different indications, so there is no accurate way to answer this question without more detailed information.
For example, if you are having pulsed dye laser treatment for congenital facial capillary malformation (port wine stain) removal, you would be undergoing a laser treatment as often as every two months for multiple treatment sessions (often 10 or more, for maximum lightening). For rosacea vessel treatment, you might have the same exact laser utilized only once, and not need another treatment ever (or for many years, since the rosacea is not "cured," only the vessels eliminated).
For laser resurfacing (treatment of wrinkles, acne scars, or texture/color irregularities) you might have either a CO2 or erbium/YAG laser utilized (or even a third-generation combination CO2--erbium/YAG laser), and it could be ablative or fractional. Ablative usually requires only one treatment, whereas fractional (since each laser session treats only a fraction of the skin) takes 3-4 operations.
IPL or BBL is not even laser treatment (Intense Pulsed Light or BroadBand Light), but is often incorrectly called that by the ignorant, lazy, or (very) poorly informed; these are often done more than once as required. Some are even "brand-named" like Fotofacial etc. and are not laser treatments, but are usually listed under laser treatments by laser spas or clinics to capitalize on the public's fascination with lasers.
Superficial laser refreshing (usually erbium/YAG laser at low power) can be done as long as your skin is healed between each session, and as long as your money lasts, but there is some down-time each time!
So, it really depends. But if you aren't getting this information from your laser provider, you should probably go elsewhere where the information and experience reassure you of the laser surgeon's expertise and safety. Best wishes! Dr. Tholen