Bought vacant land in 2017. 2.55 acres. Land was not approved for septic. We paid for creation of an approved leach field in 2018. $18,600 spent. Can we deduct this?

[JohnW15]

If you use this property for personal use, the IRS doesn't allow any deductions on the improvements. You can only add those improvement expenses to the cost basis of your property, which is important if and when you sell it.   Please see the TurboTax FAQ "What is the definition of cost basis?" below for more information on this.

https://ttlc.intuit.com/replies/4227651

However, if you use this land for business use -- rental, for example -- then you can deduct the capital items by depreciating them over a period of time instead of all at once.