One of my tenants wants me to repaint his apartment. Do I have any legal obligation to make this kind of cosmetic improvement?
No state law requires you to repaint the interior, but local ordinances might. For example, a New York City ordinance requires repainting every three years, or sooner if the walls become unsanitary through no fault of the tenant. (N.Y.C. Admin. Code § 27-2013.) Local ordinances addressing cosmetic issues are rare, though.
Unless the paint in your rental unit is creating a habitability problem—for example, paint that's so thick around a window that the window can't be opened—you typically don't have a legal obligation to repaint. Lead-based paint, on the other hand, can create all sorts of legal problems for landlords. You'll want to make sure that your rental complies with all lead-based paint laws, or face potential liability if someone is injured. For example, if a child becomes ill from eating lead-based paint chips, a court might find you liable.
Even if you're not legally required to repaint, you might want to consider accommodating the tenant's request. Choosing—and retaining—good tenants is key to having a thriving landlord business. If the request to repaint is made by a tenant you'd hate to lose, it makes sense to approve the request. Painting the apartment is likely less of a hassle and less expensive than advertising the rental and screening potential tenants. Plus, if your current tenant left for a better-maintained rental, it sounds like you'd probably want to repaint anyway before showing the place to prospective tenants.
One option—if you trust your tenant—is to let the tenant do the painting. Be sure to get any agreement in writing, spelling out details such as the budget you authorize for spending on the paint and supplies, the completion date, and the color of the paint.
The same advice above applies to requests for other cosmetic improvements, such as replacing drapes or carpet. Most of the time, there won't be a local ordinance addressing the issue, so as long as the condition doesn't pose a health or safety problem, you aren't legally required to replace or repair it. However, it might make sense to do so in order to retain a quality tenant.