(a) Overview. This section provides rules for applying section 263(a) to amounts paid to improve tangible property. Paragraph (b) of this section provides definitions. Paragraph (c) of this section provides rules for coordinating this section with other provisions of the Internal Revenue Code (Code). Paragraph (d) of this section provides for leasehold improvements. Paragraph (g) of this section provides special rules for determining improvement costs in particular contexts, including indirect costs incurred during an improvement, removal costs, aggregation of related costs, and regulatory compliance costs. Paragraph (h) of this section provides a safe harbor for small taxpayers. Paragraph (i) provides a safe harbor for routine maintenance costs. Paragraph (j) of this section provides rules for determining whether amounts are paid for betterments to the unit of property. Paragraph (k) of this section provides rules for determining whether amounts are paid to restore the unit of property. Paragraph (l) of this section provides rules for amounts paid to adapt the unit of property to a new or different use. Paragraph (m) of this section provides an optional regulatory accounting method. Paragraph (n) of this section provides an election to capitalize repair and maintenance costs consistent with books and records. Paragraphs (o) and (p) of this section provide for the treatment and recovery of amounts capitalized under this section. Paragraphs (q) and (r) of this section provide for accounting method changes and state the effective/applicability date for the rules in this section.